Retention versus sacrifice of the posterior cruciate ligament in total knee arthroplasty for treating osteoarthritis

  • Review
  • Intervention

Authors


Abstract

Background

The functional and clinical basis on which to choose whether or not to retain the posterior cruciate ligament during total knee arthroplasty surgery remained unclear after a Cochrane systematic review and meta-analysis in 2005, which contained eight clinical trials. Several new trials have been conducted since then. Hence, an update of the review was performed.

Objectives

Our aim was to assess the benefits and harms of retention compared to sacrifice of the posterior cruciate ligament in total knee arthroplasty in patients with osteoarthritis of the knee.

Search methods

An extensive search was conducted in CENTRAL, MEDLINE (PubMed), EMBASE, Web of Science, CINAHL, Academic Search Premier, Current Contents Connect and Science Direct. All databases were searched, without any limitations, up to 6 December 2012. References of the articles were checked and citation tracking was performed.

Selection criteria

Randomised and quasi-randomised controlled trials comparing retention with sacrifice of the posterior cruciate ligament in primary total knee arthroplasty in patients with osteoarthritis of the knee.

Data collection and analysis

Data were collected with a pre-developed form. Risk of bias was assessed independently by two authors (WV, LB). The level of evidence was graded using the GRADE approach. Meta-analysis was performed by pooling the results of the selected studies, when possible. Subgroup analyses were performed for posterior cruciate ligament retention versus sacrifice using the same total knee arthroplasty design, and for studies using a posterior cruciate ligament retaining or posterior stabilised design, and when sufficient studies were available subgroup analyses were performed for the same brand.

Main results

Seventeen randomised controlled trials (with 1810 patients and 2206 knees) were found, described in 18 articles. Ten of these were new studies compared to the previous Cochrane Review. One study from the original Cochrane review was excluded. Most new studies compared a posterior cruciate ligament retaining design with a posterior stabilised design, in which the posterior cruciate ligament is sacrificed (a posterior stabilised design has an insert with a central post which can engage on a femoral cam during flexion).

The quality of evidence (graded with the GRADE approach) and the risk of bias were highly variable, ranging from moderate to low quality evidence and with unclear or low risk of bias for most domains, respectively.

The performance outcome 'range of motion' was 2.4 ° higher in favour of posterior cruciate ligament sacrifice (118.3 ° versus 115.9 °; 95% confidence interval (CI) of the difference 0.13 to 4.67; P = 0.04), however the results were heterogeneous. On the item 'knee pain' as experienced by patients, meta-analysis could be performed on the Knee Society knee pain score; this score was 48.3 in both groups, yielding no difference between the groups. Implant survival rate could not be meta-analysed adequately since randomised controlled trials lack the longer term follow-up in order to evaluate implant survival. A total of four revisions in the cruciate-retention and four revisions in the cruciate-sacrifice group were found. The well-validated Western Ontario and McMaster Universities osteoarthritis index (WOMAC) total score was not statistically significantly different between the groups (16.6 points for cruciate-retention versus 15.0 points for cruciate-sacrifice). One study reported a patient satisfaction grade (7.7 points for cruciate-retention versus 7.9 points for cruciate-sacrifice on a scale from 0 to 10, 10 being completely satisfied) which did not differ statistically significantly. Complications were distributed equally between both groups. Only one study reported several re-operations other than revision surgery; that is patella luxations, surgical manipulation because of impaired flexion.

The mean functional Knee Society Score was 2.3 points higher (81.2 versus 79.0 points; 95% CI of the difference 0.37 to 4.26; P = 0.02) in the posterior cruciate ligament sacrificing group. Results from the outcome Knee Society functional score were homogeneous. All other outcome measures (extension angle, knee pain, adverse effects, clinical questionnaire scores, Knee Society clinical scores, radiological rollback, radiolucencies, femorotibial angle and tibial slope) showed no statistically significant differences between the groups. In the subgroup analyses that allowed pooling of the results of the different studies, no homogeneous statistically significant differences were identified.

Authors' conclusions

The methodological quality and the quality of reporting of the studies were highly variable. With respect to range of motion, pain, clinical, and radiological outcomes, no clinically relevant differences were found between total knee arthroplasty with retention or sacrifice of the posterior cruciate ligament. Two statistically significant differences were found; range of motion was 2.4 ° higher in the posterior cruciate ligament sacrificing group, however results were heterogeneous; and the mean functional Knee Society Score was 2.3 points higher in the posterior cruciate ligament sacrificing group. These differences are clinically not relevant.

Résumé scientifique

Conservation ou sacrifice du ligament croisé postérieur lors d’arthroplastie totale du genou pour le traitement de l'arthrose

Contexte

Les résultats fonctionnels et cliniques permettant de décider de préserver ou de retirer le ligament croisé postérieur (LCP) lors d'une arthroplastie totale du genou demeuraient incertains, ceci à la suite d’une revue systématique Cochrane et d’une méta-analyse en 2005, qui comprenaient huit essais cliniques. Plusieurs nouveaux essais ont depuis été menés. Ce pourquoi une mise à jour de la revue a été réalisée.

Objectifs

Notre objectif était d'évaluer les avantages et les inconvénients entre la préservation et le retrait du ligament croisé postérieur dans l'arthroplastie totale du genou chez les patients souffrant d'arthrose du genou.

Stratégie de recherche documentaire

Une recherche exhaustive a été menée dans CENTRAL, MEDLINE (PubMed), EMBASE, Web of Science, CINAHL, Academic Search Premier, Current Contents Connect et Science Direct. Toutes les bases de données ont été consultées, sans limitation méthodologique, jusqu'au 6 décembre 2012. Les références des articles ont été examinées et le suivi des citations a été réalisé.

Critères de sélection

Essais contrôlés randomisés et quasi-randomisés comparant la préservation et le retrait du ligament croisé postérieur dans l'arthroplastie totale du genou chez les patients souffrant d'arthrose du genou.

Recueil et analyse des données

Les données ont été recueillies avec un formulaire prédéfini. Le risque de biais a été évalué de manière indépendante par deux auteurs (WV, LB). Le niveau de preuve a été évalué à l'aide de l'approche GRADE. La méta-analyse a été réalisée en combinant les résultats des études sélectionnées, lorsque cela était possible. Les analyses en sous-groupe ont été réalisées pour comparer la préservation au retrait du ligament croisé postérieur en utilisant la même forme d’arthroplastie totale du genou, pour les études utilisant un ligament croisé postérieur préservé ou stabilisé. De plus, lorsque suffisamment d'études étaient disponibles, les analyses en sous-groupe ont été réalisées pour la même marque.

Résultats principaux

Dix-sept essais contrôlés randomisés (totalisant 1 810 patients et 2 206 genoux) ont été trouvés et décrits dans 18 articles. Dix d’entre eux étaient de nouvelles études comparées à la précédente revue Cochrane. Une étude de la revue originale Cochrane a été exclue. La plupart des nouvelles études comparaient le ligament croisé postérieur préservé à un postérieur stabilisé, dans lequel le ligament croisé postérieur est retiré (un postérieur stabilisé possède une insertion avec un tenon central qui peut s’enclencher sur une came fémorale au cours de la flexion).

La qualité des preuves (évaluée avec l'approche GRADE) et le risque de biais étaient très variable, allant de qualité modérée à faible et avec des risques de biais incertains ou faibles dans la plupart des domaines, respectivement.

Les performances des critères de jugement concernant l'amplitude de mouvement était de 2,4° plus élevées lors de ligament croisé postérieur retiré (118,3° versus 115,9°; intervalle de confiance (IC) de la différence de 0,13 à 4,67 ; P =0,04), cependant les résultats étaient hétérogènes. Concernant le score de la douleur ressentie par les patients, une méta-analyse a pu être effectuée avec Knee Society; ce score était de 48,3 dans les deux groupes, n’aboutissant à aucune différence entre les groupes. Le taux de survie des implants n'a pas pu être méta-analysé de manière adéquate, les essais contrôlés randomisés manquant de suivi à plus long terme. Un total de quatre révisions dans le groupe de ligament préservé et quatre révisions dans le groupe de ligament retiré a été trouvé. Le score total de l’indice sur l’ostéoarthrite, élaboré par les Universités de Western Ontario et de McMaster (WOMAC), n'était pas statistiquement significativement différent entre les groupes (16,6 points pour le groupe de ligament préservé versus 15,0 points pour le groupe de ligament retiré). Une étude rapportait un niveau de satisfaction du patient (7,7 points pour le groupe de ligament préservé versus 7,9 points pour le groupe de ligament retiré sur une échelle de 0 à 10, 10 étant des patients entièrement satisfaits) qui ne différait pas de façon statistiquement significative. Des complications étaient réparties de manière égale entre les deux groupes. Seule une étude a rapporté plusieurs ré-opérations, autres que les chirurgies de révision, qui correspondaient à une luxation de la rotule, manipulation chirurgicale en raison d’une flexion altérée.

Le score de Knee Society concernant un fonctionnement adéquat était de 2,3 points plus élevé (81,2 versus 79,0 points ; IC à 95% de la différence de 0,37 à 4,26 ; P =0,02) dans le groupe de ligament croisé postérieur retiré. Les résultats de Knee Society concernant un fonctionnement adéquat étaient homogènes. Toutes les autres mesures de résultats (l’angle d’extension, la douleur du genou, les effets indésirables, les questionnaires pour le scores cliniques, les scores cliniques de Knee Society, les radiologies, les radiotransparences, l’angle fémoro-tibial et la pente du tibia) n’ont montré aucune différence statistiquement significative entre les groupes. Dans les analyses de sous-groupes, qui ont permis de combiner les résultats des différentes études, aucune différence statistiquement significative homogène n’a été identifiée.

Conclusions des auteurs

La qualité méthodologique et la qualité des rapports des études étaient très variables. En ce qui concerne l'amplitude de mouvement, la douleur, les cliniques, les critères de jugement radiologiques, aucune différence n'a été observée entre l'arthroplastie totale du genou avec un ligament croisé postérieur préservé ou retiré. Deux différences statistiquement significative ont été trouvé ; l'amplitude de mouvement était de 2,4° plus élevée dans le groupe du ligament croisé postérieur retiré, cependant, les résultats étaient hétérogènes ; et le score de Knee Society concernant un fonctionnement adéquat était de 2,3 points plus élevé dans le groupe de ligament croisé postérieur retiré. Ces différences ne sont cliniquement pas pertinentes.

Plain language summary

Retention versus sacrifice of the posterior cruciate ligament in total knee replacement for the treatment of osteoarthritis

Researchers in The Cochrane Collaboration have conducted a review of two types of knee replacement surgery for people with knee osteoarthritis. In one type, the posterior cruciate ligament is kept and in the other, it is removed. After searching for all relevant studies, they found 17 studies with up to 1810 patients.

The review shows that in people with osteoarthritis who have the posterior cruciate ligament preserved during total knee replacement surgery:

- this may not improve their range of motion, pain, function and patient satisfaction compared with removing the ligament.

We do not have precise information about side effects and complications, especially rare but serious side effects. Possible side effects may include infection, pain, and the need to have further surgery.

What is osteoarthritis and what is the posterior cruciate ligament?

Osteoarthritis (OA) is a disease of the joints, such as your knee or hip. When the joint loses cartilage, the bone may grow abnormally to try and repair the damage and make things worse. For example, it can make the joint painful and unstable. This can affect your physical function or ability to use your knee.

In some people, damage and pain in the knee from arthritis may be severe enough to require surgery. In total knee replacement surgery, a surgeon removes the damaged joint surface and replaces it with a metal and plastic implant.

The posterior cruciate ligament provides support and stable movement of the knee. In total knee replacement surgery, the posterior cruciate ligament can be kept in place or removed. This choice depends on the condition of the ligament, the type of total knee replacement selected or preference of the surgeon. When the ligament is removed, a special peg is used to provide stability and give your knee forward and backward movement with the tibia stabilised in relation to the femur.

What happens to people who have the posterior cruciate ligament preserved or removed during total knee replacement surgery

Range of motion (range of motion is the distance your knee can move from being bent to being fully extended. A lower range of motion is worse; you can’t bend or stretch your knee fully)

- People who had their posterior cruciate ligament preserved had 2 ° less range of motion compared to those who had it removed. This may be a result of chance
- People who had their posterior cruciate ligament removed had a range of motion of 118 ° of a possible 0 ° to 140 °
- People who had their posterior cruciate ligament preserved had a range of motion of 116 ° of a possible 0 ° to 140 °

Knee pain (lower score means worse pain)

- People who had their posterior cruciate ligament preserved rated their pain to be the same as those who had it removed. This may be a result of chance

- People who had their posterior cruciate ligament preserved or removed rated their pain to be 48 on a scale of 0 to 50

Health related quality of life and functional measures (higher means worse)

- People who had their posterior cruciate ligament preserved rated their quality of life to be 1 point worse than those who had it removed. This may be a result of chance

- People who had their posterior cruciate ligament preserved rated their quality of life to be 16 on a scale of 0 to 100

- People who had their posterior cruciate ligament removed rated their quality of life to be 15 on a scale of 0 to 100

Patient satisfaction (lower means worse)

- People who had their posterior cruciate ligament preserved rated their satisfaction the same as those who had it removed. This may be a result of chance

- People who had their posterior cruciate ligament preserved or removed rated their satisfaction to be 8 on a scale of 0 to 10

Complications and the need to have further surgery

- There were no differences in the number of revision surgeries, complications, or other further surgeries in people who had their posterior cruciate ligament preserved or removed.

Résumé simplifié

Conservation ou sacrifice du ligament croisé postérieur lors d’arthroplastie totale du genou pour le traitement de l'arthrose

Des chercheurs de la Collaboration Cochrane ont mené une revue de deux types de chirurgie de remplacement du genou pour les personnes souffrant d'arthrose du genou. Dans un type, le ligament croisé postérieur est maintenu et dans l'autre, il est retiré. Après avoir recherché toutes les études pertinentes, ils ont identifié 17 études totalisant 1 810 patients.

La revue montre que chez les patients souffrant d'arthrose qui ont le ligament croisé postérieur préservé pendant la chirurgie de remplacement total du genou :

- cela pourrait ne pas améliorer l’amplitude de mouvement, la douleur, la fonction et la satisfaction du patient par rapport au retrait du ligament.

Nous ne disposons pas d’informations précises concernant les effets secondaires et les complications, en particulier les effets secondaires rares mais sévères. Les effets secondaires potentiels peuvent inclure une infection, de la douleur et la nécessité d'une intervention chirurgicale supplémentaire.

Qu'est -ce que l'arthrose et qu'est -ce que le ligament croisé postérieur ?

L'arthrose est une maladie des articulations affectant par exemple le genou ou la hanche. Lorsque l'articulation perd du cartilage, l'os peut grandir anormalement pour essayer de réparer le dommage, ce qui aggrave la situation. Par exemple, cela peut provoquer une articulation douloureuse et instable. Cela peut compliquer la fonction physique ou la capacité à utiliser ses genoux.

Chez certains patients atteints d'arthrite, les lésions et la douleur du genou peuvent être suffisamment sévères pour justifier une intervention chirurgicale. Lors du remplacement total du genou, un chirurgien retire la surface de l'articulation endommagée et la remplace par un implant en plastique et métallique.

Le ligament croisé postérieur soutient le genou et stabilise le mouvement. Dans la chirurgie de remplacement total du genou, le ligament croisé postérieur peut être conservé ou retiré. Ce choix dépend de l'état du ligament, du type de prothèse du genou ou du type d'intervention préférée par le chirurgien. En cas d'ablation du ligament, une prothèse spéciale du genou est utilisée pour apporter une stabilité et guider le mouvement du genou d'avant en arrière avec le tibia stabilisé par rapport au fémur.

Qu’arrivent-ils aux patients qui ont le ligament croisé postérieur conservé ou retiré pendant la chirurgie de remplacement total du genou ?

Amplitude de mouvement (l’amplitude de mouvement est la distance entre le genou plié et complètement déplié. Une réduction de l'amplitude de mouvement est mauvaise; les genoux ne peuvent se plier ou se déplier totalement)

- Les patients ayant conservé leur ligament croisé postérieur avaient une amplitude de mouvement diminuée de 2° par rapport à ceux dont le ligament avait été retiré. Ce résultat peut être dû au hasard
- Les patients dont le ligament croisé postérieur avait été retiré présentaient une amplitude de mouvement de 118° avec une possibilité de 0° à 140°
- Les patients ayant eu leur ligament croisé postérieur préservé présentaient une amplitude de mouvement de 116° avec une possibilité de 0° à 140°.

La douleur du genou (le score le plus faible signifie une douleur plus accentuée)

- La douleur des patients ayant eu leur ligament croisé postérieur préservé était similaire à ceux dont leur ligament avait été retiré. Ce résultat peut être dû au hasard.

- Les patients ayant eu leur ligament croisé postérieur préservé ou retiré ont qualifié leur douleur comme étant de 48 sur une échelle de 0 à 50.

La qualité de vie liée à la santé et les mesures fonctionnelles (score plus élevé signifie une qualité de vie aggravée)

- Les patients ayant eu leur ligament croisé postérieur préservé ont évalué leur qualité de vie être de 1 point plus mauvais que ceux dont leur ligament avait été retiré. Ce résultat peut être dû au hasard.

- Les patients ayant eu leur ligament croisé postérieur préservé ont évalué leur qualité de vie être de 16 sur une échelle de 0 à 100.

- Les personnes ayant eu leur ligament croisé postérieur retiré ont évalué leur qualité de vie être de 15 sur une échelle de 0 à 100.

La satisfaction du patient (score plus faible signifie une satisfaction plus mauvaise)

- La satisfaction des patients ayant eu leur ligament croisé postérieur préservé était similaire à ceux dont leur ligament avait été retiré. Ce résultat peut être dû au hasard.

- Les personnes ayant eu leur ligament croisé postérieur préservé ou retiré ont qualifié leur satisfaction être de 8 sur une échelle de 0 à 10.

Les complications et la nécessité de procéder à une intervention chirurgicale supplémentaire

- Il n’y avait aucune différence concernant le nombre de révisions de chirurgie, de complications, ou d'autres chirurgies supplémentaires chez les patients ayant eu leur ligament croisé postérieur préservé ou retiré.

Notes de traduction

Traduit par: French Cochrane Centre 14th January, 2014
Traduction financée par: Ministère du Travail, de l'Emploi et de la Santé Français

எளியமொழிச் சுருக்கம்

முதுமை மூட்டழற்சி சிகிச்சைக்கு முழு மூட்டுச் சீரமைப்பு சிகிச்சையின் போது பின்புற கருசியேட் தசைநாரை தக்கவைத்தல் மற்றும் நீக்கப்படுதலை ஒப்பிடுதல்

காக்ரேன் ஒருங்கிணைவில் உள்ள ஆராய்ச்சியாளர்கள் முதுமை மூட்டழற்சி உள்ளவரகளுக்கு இரண்டு வகை முழங்கால் மாற்று அறுவை சிகிச்சை விளைவுகள் குறித்து ஒரு திறனாய்வு நடத்தினர். ஒரு வகையில் பின்புற கருசியேட் தசைநார் நீக்கப்படுகிறது மற்றொன்றில் அது பாதுகாக்கப்படுகிறது. இது தொடர்பாக அனைத்து ஆய்வுகளையும் தேடியதில், அவர்கள் 1810 நோயாளிகளை உள்ளடக்கிய 17 ஆய்வுகளை கண்டறிந்தனர்.

இந்த ஆய்வு கீல்வாதத்தால் பாதிக்கப்பட்டவர்களுக்கு பின்புற கருசியேட் தசைநார் பாதுகாக்கப்பட முழு முழங்கால் மாற்று அறுவை சிகிச்சையின் காண்பிப்பதாவது:

–தசைநார் நீக்கியதுடன் ஒப்பிடுகையில் இது இயக்க வரம்பு, வலி, செயல்பாட்டு திறன் மற்றும் நோயாளியின் மனநிறைவை மேம்படுத்தாது

எங்களிடம் பக்கவிளைவுகள் மற்ற சிக்கல்கள், குறிப்பாக அரிதான ஆனால் தீவிர பக்கவிளைவுகள் பற்றிய துல்லியமான தகவல் எதுவும் இல்லை. தொற்று மற்றும் வலி மேலும் மோசமடைதல் போன்ற பக்க விளைவுகள் ஏற்படலாம். இதனால் மேலும் அறுவைசிகிச்சை தேவைப்படலாம்

முதுமை மூட்டழற்சி என்றால் என்ன மற்றும் பின்புற கருசியேட் தசைநார் என்றால் என்ன?

முதுமை மூட்டழற்சி என்பது உங்கள் முழங்கால் அல்லது இடுப்பு போன்ற மூட்டுகளைத் தாக்கும் நோயாகும். உங்கள் மூட்டு அதன் குருத்தெலும்பை இழக்கும் போது, எலும்பானது அபரிமிதமாக வளர்ந்து, அதன் பாதிப்பை சரி செய்ய முயற்சிக்கும். ஆனால், இதனை சரி செய்வதற்குப்பதில், நிலைமையைமேலும் செய்கிறது. உதாரணமாக, எலும்பானது உருவிழந்து,மூட்டுவலியையும், ஸ்திரமற்ற மூட்டையும் உண்டாக்கும். இது உங்கள் உடல் செயல்பாடு, அல்லது உங்கள் முழங்கால் மூட்டினை உபயோகிக்கும் செயல்பாட்டு திறனைப் பாதிக்கலாம்.

சிலருக்கு, முழங்கால் மூட்டு சேதம் மற்றும் வலி அறுவை சிகிச்சை தேவைப்படும் அளவுக்கு கடுமையாக இருக்கலாம். முழு முழங்கால் மாற்று அறுவை சிகிச்சையின் போது சேதமடைந்த மூட்டு மேற்பரப்பை உலோக மற்றும் பிளாஸ்டிக் உள்வைப்பு கொண்டு மருத்துவர் மாற்றுவார்.

ன்புற குருசியேட் தசைநார், முழங்கால் மூட்டின் ஸ்திரமான இயக்கத்திற்கு ஆதரவு அளிக்கிறது. முழங்கால் மாற்று அறுவை சிகிச்சையில் பின்புற குருசியேட் தசைநார் பாதுகாக்கப் படுகிறது அல்லது நீக்கப்படுகிறது. தசைநார் நிலை, தேர்ந்தெடுக்கப்பட்ட முழங்கால் மாற்று சிகிச்சைமுறை, அல்லது அறுவை சிகிச்சை நிபுணரின் விருப்பத்தை பொறுத்தே இது தேர்வு செய்யப்படுகிறது. தசைநார் நீக்கப்படும்போது மூட்டினை நிலைநிறுத்தவும், டிபியா எலும்பை தொடைஎலும்புடன் (femur) தொடர்புபடுத்தி நிலைநிறுத்தி , மூட்டிற்கு முன்நோக்கியும் பின்னோக்கியும் இயக்கம் அளிக்கவும், ஒருவித சிறப்பு ஆப்பு பயன்படுத்தப்படுகிறது.

கீல்வாதத்தால் பாதிக்கப்பட்டவர்களுக்கு பின்புற குருசியேட் தசைநார் பாதுகாக்கப்பட்ட அல்லது நீக்கப்பட்ட முழு முழங்கால் மாற்று அறுவை சிகிச்சையினால் என்ன விளைவு ஏற்படுகிறது:

இயக்க வரம்பு (உங்களுடைய முழங்கால் அவ்வளவு தூரம் நீடிய நிலையில் இருந்து மடக்க முடிவது -இயக்க வரம்பு) இயக்க வரம்பு குறைவாக இருந்தால் அது மோசமான நிலை; உங்களால் முழுமையாக மடக்கவோ நீட்டவோ முடியாது)

பின்புற கருசியேட் தசைநார் அகற்றப்பட்டவர்களை ஒப்பிடும்போது அது அதனை பாதுகாக்கப்பட்டவர்களுக்கு அவர்களின் இயக்க வரம்பு 2 ° குறைவாக இருந்தது இது வாய்ப்பின் விளைவாக இருக்கலாம்.
கருசியேட் தசைநார் நீக்கப்பட்டவர்களில் இயக்க வரம்பு 118 ° (சாத்தியமான வரம்பு 0 ° to 140 °) ஆக இருந்தது
குருசியேட் தசைநார் நீக்கப்படாதவர்களில் இயக்க வரம்பு 116° (சாத்தியமான வரம்பு 0 ° to 140 °) ஆக இருந்தது.

மூட்டு வலி (குறைவான மதிப்பெண் என்றால் வலி மோசமானது)

-பின்புற கருசியேட் தசைநார் பாதுகாக்கப்பட்டவர்கள் அவர்களின் வலியை அதனை நீக்கியவர்கள் போலவே மதிப்பிட்டனர். இந்த முடிவு வாய்ப்பின் விளைவாக இருக்கலாம்.

- பின்புற கருசியேட் தசைநார் சிகிச்சை பாதுகாக்கப்பட்ட அல்லது நீக்கப்பட்ட வர்கள் 0 முதல் 50 புள்ளிகள் வரையிலான ஒரு அளவீட்டில், அவர்களின் வலியை 48 புள்ளிகளாக பதிவிட்டனர்.

ஆரோக்கியம் சார்ந்த வாழ்க்கை தரம் மற்றும் செயல்பாட்டு திறன் அளத்தல் (அதிகம் என்றால் மோசமான நிலை)

-பின்புற குருசியேட் தசைநார் பாதுகாக்கப்பட்டவர்கள் அவர்களின் வாழ்க்கைத்தரத்தை தசைநார் அகற்றப்பட்டவர்களைவிட ஒரு புள்ளி மோசம் என்று மதிப்பிட்டனர். இந்த முடிவு வாய்ப்பின் விளைவாக இருக்கலாம்.

- பின்புற கருசியேட் தசைநார் பாதுகாக்கப்பட்டவர்கள் 0-100 புள்ளி கொண்ட அளவுகோலில் தங்கள் வாழ்க்கை தரம் 16 புள்ளிகள் என்று மதிப்பிட்டுள்ளனர்.

- பின்புற கருசியேட் தசைநார் நீக்கப்பட்டவர்கள் 0 முதல் 100 புள்ளிகள் வரையிலான ஒரு அளவீட்டில், அவர்களின் வாழ்க்கை தரத்தை 15 என்று பதிவிட்டனர்.

நோயாளி மனநிறைவு (குறைவு என்றால் மோசமான நிலை)

பின்புற குருசியேட் தசைநார் பாதுகாக்கப்பட்டவர்கள் அவர்களின் மனநிறைவை தசைநார் நீக்கபட்டவர்கள் போலவே மதிப்பிட்டனர். இந்த முடிவு வாய்ப்பின் விளைவாக இருக்கலாம்.

- பின்புற கருசியேட் தசைநார் சிகிச்சை பாதுகாக்கப்பட்ட அல்லது நீக்கப்பட்டவர்கள் 0 முதல் 10 புள்ளிகள் வரையிலான ஒரு அளவீட்டில், அவர்களின் மனநிறைவு 8 புள்ளிகளாக பதிவிட்டனர்.

சிக்கல்கள் மற்றும் மேலும் அறுவை சிகிச்சை தேவைபடு்தல்

- பின்புற கருசியேட் தசைநார் பாதுகாக்கப்பட்ட அல்லது நீக்கப்பட்ட அறுவை சிகிச்சைகளுக்கு இடையே திருத்தல் அறுவை சிகிச்சைகளின் எண்ணிக்கை, சிக்கல்கள் அல்லது மற்ற அறுவை சிகிச்சைகளின் தேவைகளில் எந்த வித்தியாசமும் இல்லை.

மொழிபெயர்ப்பு குறிப்புகள்

மொழிபெயர்ப்பாளர்: சி.இ.பி.என்.ஆர் குழு

Summary of findings(Explanation)

Summary of findings for the main comparison. Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs)
  1. 1 Median follow-up: 2 years
    2 Risk of bias individual studies, see risk of bias tables
    3 Some studies have high risk of bias. Relatively too many unclear risks
    4 Results of Catani 2004 inconsistent with the rest
    5 More than 400 arthroplasties
    6 Relatively too many unclear risks of bias

    7 Some studies reported complications after several months. Mean follow-up of other endpoints was > 1 year

    8 Complications reported in the cruciate-sacrifice group: 4 anterior knee pain, 4 limited range of motion, 1 deep venous thrombosis, 3 instability, 3 femoral notching, 3 aseptic loosening, 3 (deep) infection

    9 Complications reported in the cruciate-retention group: 6 anterior knee pain, 10 limited range of motion, 0 deep venous thrombosis, 3 instability, 2 femoral notching, 2 aseptic loosening, 3 (deep) infection, 2 ligament laxity, 1 ligament tightness

    10 Not sufficient data reported to calculate standard error, range or confidence interval

Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs)
Patient or population: Patients receiving total knee arthroplasty with or without posterior stabilised design for the treatment of osteoarthritis
Settings: Hospital
Intervention: Posterior cruciate ligament retention
Comparison: Posterior cruciate ligament sacrifice
OutcomesComparative risksRelative effect

No. of patients

(% of total)

No. of studies

(% of total)

Quality of the evidence
(GRADE)
Comments
Cruciate-sacrifice Cruciate-retention

Performance based measures - Range of motion

(possible range 0 (worst) to 140 (maximal) degrees)

Follow-up: 12-78 months1

The mean range of motion in the cruciate-sacrifice group was 118.3 degrees (± SE 0.53)

The mean range of motion in the cruciate-retaining group 2.40 lower

(4.61 lower to 0.13 higher)

 

Total No. of patients: 1,119

(62%)

Total No. of knees: 1,440

(65%)

11 studies

(65%)

⊕⊕⊝⊝
low 2,3,4,5

Absolute difference 2.40 lower

(4.61 lower to 0.13 higher)

Relative percent change: -2.0% (3.9% lower to 0.1% higher)

Not statistically significant.

Knee pain

Knee Society Score, sub score pain

(possible range of points 0 (severe pain) - 50 (no pain))

Follow-up: 24-87 months years

The mean knee pain score in the cruciate-sacrifice group was 48.3 points (± SE 0.54)

The mean knee pain score in the cruciate-retention group was 0.01 higher

(1.40 lower to 1.43 higher)

 

Total No. of patients: 656

(36%)

Total No. of knees: 1,004

(46%)

4 studies

(24%)

⊕⊕⊕⊝
moderate 2,5,6

Absolute difference: 0.01 higher

(1.40 lower to 1.43 higher)

Relative percent change: 0.0% (2.9% lower to 3.0% higher)

Not statistically significant.

Survival rate of the implant

(Revision surgery reported)

Follow-up: 17-87 months

See commentSee commentNot estimable

Total No. of patients: 926

(51%)

Total No. of knees: 1,229

(56%)

7 studies

(41%)

See comment

Insufficient data provided.

Incidental remarks on implant survival could be derived from 7 studies.

One study Misra 2003 reported 2 revisions in de cruciate-retention group, Chaudhary 2008 1 in the cruciate-retention group, Harato 2008 1 in the cruciate-retention group and 3 in the sacrifice group. Aglietti 2005 1 revision in the cruciate-sacrifice group due to septic loosening

Kim 2009, Yagishita 2012 and Tanzer 2002 specifically reported no revision surgery had occurred during follow-up

Health related quality of life measures and functional measures with validated instruments (WOMAC, range 0-100, higher scores indicate worse pain, stiffness and functional limitations)

Follow-up: 24-87 months

The mean WOMAC total score in the cruciate-sacrifice group was 15.0 points (± SE 1.2)

The mean WOMAC total score in the cruciate-retention group was 0.78 higher

(1.51 lower to 3.07 higher)

 

Total No. of patients: 501

(28%)

Total No. of knees: 531

(24%)

4 studies

(24%)

⊕⊕⊝⊝
low 2,3,4,5

Absolute difference: 0.78 higher

(1.51 lower to 3.07 higher)

Relative percent change: 5.2% (10.0% lower to 20.5% higher)

Not statistically significant.

Global assessment (patient)

Patient satisfaction on scale 0 (not at all satisfied) to 10 (completely satisfied)

Follow-up: 12-83

months

The mean satisfaction score in the cruciate-sacrifice group was 7.9 10The mean satisfaction score in the cruciate-retention group was 0.2 lower 10 

Total No. of patients: 103

(6%)

Total No. of knees: 105

(5%)

1 study

(6%)

⊕⊕⊝⊝
low 2,5

Absolute difference: 0.2 lower 10

Relative percent change: -2.5% 10

Not statistically significant.

Complications

Follow-up: 8-87 months7

See commentSee commentNot estimable

Total No. of patients: 1,252

(69%)

Total No. of knees: 1,635

(74%)

11 studies

(65%)

See commentDue to the very diverse way of reporting and defining complications combining data for quantitative analysis was not possible8,9

Re-operation rate (not involving implant change, short and long term)

Follow-up: 24 months

See commentSee commentNot estimable

Total No. of patients: 40

(2%)

1 study

(6%)

See comment Catani 2004 reported 4 re-operations; 3 patella luxations (2 in cruciate-sacrificing, 1 in cruciate-retention group) and 1 surgical manipulation due to lack of range of motion (in the cruciate-retention group)
CI: Confidence interval; KSS: Knee Society Score, WOMAC: Western Ontario and McMasters Universities Osteoarthritis Index. NA: not applicable
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Summary of findings 2 Posterior cruciate ligament retention versus sacrifice (using the same arthroplasty design)

Summary of findings 2. Posterior cruciate ligament retention versus sacrifice (using the same arthroplasty design)
  1. 1 Risk of bias individual studies, see risk of bias tables
    2 Relatively too much unclear risks of bias
    3 Inconsistent results from the studies
    4 < 400 arthroplasties in analysis

    5 Complications reported in the cruciate-sacrifice group: 3 instability, 3 aseptic loosening, 2 stiffness

    6 Complications reported in the cruciate-retention group: 3 instability, 1 infection (deep), 2 aseptic loosening, 2 stiffness, 2 ligament laxity, 1 ligament tightness

    7 Not sufficient data reported to calculate standard error, range or confidence interval

Posterior cruciate ligament retention versus sacrifice (using the same arthroplasty design)
Patient or population: Patients receiving total knee arthroplasty with or without resection of the posterior cruciate ligament for the treatment of osteoarthritis
Settings: Hospital
Intervention: Posterior cruciate ligament retention
Comparison: Posterior cruciate ligament sacrifice
OutcomesComparative risks Relative effect

No. of patients

(% of total)

No of studies

(% of total)

Quality of the evidence
(GRADE)
Comments
Cruciate-sacrifice Cruciate-retention

Performance based measures - Range of motion

(possible range 0 (worst) to 140 (maximal) degrees)

Follow-up: 12-78 months

The mean range of motion in the cruciate-sacrifice group was 114.1 degrees (± SE 0.82)

The mean range of motion in the cruciate-retention group was 2.7 degrees lower

(8.71 lower to 3.32 higher)

 

Total No. of patients: 405

(22%)

Total No. of knees: 414

(19%)

4 studies

(24%)

⊕⊝⊝⊝
very low 1,2,3,4

Absolute difference: 2.7 degrees lower

(8.71 lower to 3.32 higher)

Relative percent change: -2.4% (7.6% lower to 2.9% higher)

Not statistically significant.

Knee pain

Knee Society Score, sub score pain

(possible range 0 (severe pain) - 50 (no pain) points)

See commentSee commentNot estimable--See commentNo data in studies comparing ligament resection and sacrifice using similar arthroplasty designs

Survival rate of the implant

(Revision surgery reported)

Follow-up: 56-60 months

See commentSee commentNot estimable

Total No. of patients: 103

(6%)

Total No. of knees: 105

(5%)

1 study

(6%)

See commentInsufficient data provided. One study (Misra 2003) reported 2 revisions in the cruciate-retention group.

Health related quality of life measures and functional measures with validated instruments (WOMAC, range 0-100, higher scores indicate worse pain, stiffness and functional limitations)

Follow-up: 24-37 months

The mean WOMAC total score in the cruciate-sacrifice group was 17.0 points (± SE 1.1)

The mean WOMAC total score in the cruciate-retention group was 1.10 lower

(-5.19 lower to 2.99 higher)

 

Total No. of patients: 86

(5%)

Total No. of knees: 86

(4%)

1 study

(6%)

See comment

One study reported this outcome: Roh 2012

Absolute difference: 1.10 lower

(-5.19 lower to 2.99 higher)

Relative percent change: -6.5% (30.5% lower to 17.6%higher)

Not statisitically significant

Global assessment (patient)

Patient satisfaction on scale 0 (not at all satisfied) to 10 (completely satisfied))

Follow-up: 12-83 months

The mean satisfaction score in the cruciate-sacrifice group was 7.9 7The mean satisfaction score in the cruciate-retention group was 0.2 lower 7 

Total No. of patients: 103

(6%)

Total No. of knees: 105

(5%)

1 study

(6%)

⊕⊕⊝⊝
low 2, 4

Absolute difference: 0.2 lower 7

Relative percent change: -2.5% 7

Not statistically significant.

Complications

Follow-up: 12-78 months

See commentSee commentNot estimable

Total No. of patients: 405

(22%)

Total No. of knees: 414

(19%)

4 studies

(24%)

See commentDue to the very diverse way of reporting and defining complications combining data for quantitative analysis was not possible5,6
Re-operation rate (not involving implant change, short and long term)See commentSee commentNot estimable--See commentNo data in studies comparing ligament resection and sacrifice using similar arthroplasty designs
CI: Confidence interval. KSS: Knee Society Score, WOMAC: Western Ontaria and McMasters Universities Osteoarthritis Index. NA: not applicable
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Summary of findings 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice

Summary of findings 3. Posterior cruciate ligament retention versus posterior stabilised sacrifice
  1. 1 Relatively many studies with 'unclear' risk of bias

    2 < 400 arthroplasties in analysis

    3 Complications reported in the cruciate-sacrifice group: 2 anterior knee pain, 3 femoral notching, 1 superficial wound infection, 2 deep venous thrombosis, 1 septic loosening

    4 Complications reported in the cruciate-retention group: 1 anterior knee pain, 1 limited ROM, 2 femoral notching, 1 superficial wound infection

    5 Some studies reported complications after several months. Mean follow-up of other endpoints was > 1 year

Posterior cruciate ligament retention versus posterior stabilised sacrifice
Patient or population: Patients receiving total knee arthroplasty with or without posterior stabilised design for the treatment of osteoarthritis
Settings: Hospital
Intervention: Posterior cruciate ligament retention
Comparison: Posterior cruciate ligament sacrifice with posterior stabilised design
OutcomesMean differences (95% CI) Relative effect

No. of patients

(% of total)

No. of studies

(% of total)

Quality of the evidence
(GRADE)
Comments

Cruciate-sacrifice

(posterior stabilised)

Cruciate-retention

Performance based measures - Range of motion

(possible range 0 (worst) to 140 (maximal) degrees)

Follow-up: 1-6.5 years1

The mean range of motion in the cruciate-sacrifice group was 119.8 degrees (± SE 0.66)

The mean range of motion in the cruciate-retention group was 3.4 degrees lower

(6.32 to 0.54 lower)

 

Total No. of patients: 899

(50%)

Total No. of knees: 1,193

(54%)

8 studies

(47%)

⊕⊕⊕⊝
moderate 1

Absolute difference: -3.4 degrees (6.32 to 0.54 lower)

Relative percent change: -2.8% (5.3% lower to 0.45% higher)

Statistically significant (P = 0.02)

NNTB: 9 (5 to 51)

Knee pain

Knee Society Score, subscore pain

(possible range 0 (severe pain) - 50 (no pain) points)

Follow-up: 2-7.3 years

The mean knee pain score in the cruciate-sacrifice group was 48.3 points (± SE 0.68)

The mean knee pain score in the cruciate-retention group was 0.60 higher

(0.39 lower to 1.60 higher)

 

Total No. of patients: 471

(26%)

Total No. of knees: 780

(35%)

3 studies
(18%)
⊕⊕⊕⊝
moderate 1,2

Absolute difference: 0.60

(0.39 lower to 1.60 higher)

Relative percent change: 1.2% (0.81% lower to 3.3% higher)

Not statistically significant.

Survival rate of the implant

(Revision surgery reported)

See commentSee commentNot estimable

Total No. of patients: 802

(44%)

Total No. of knees: 1,100

(50%)

6 studies

(35%)

See comment

Insufficient data provided.

Incidental remarks on implant survival could be derived from 6 studies.

Chaudhary 2008 1 in the cruciate-retention group, Harato 2008 1 in the cruciate-retention group and 3 in the sacrifice group. Aglietti 2005 1 revision in the cruciate-sacrifice group due to septic loosening

Kim 2009, Yagishita 2012 and Tanzer 2002 specifically reported no revision surgery had occurred during follow-up

Health related quality of life measures and functional measures with validated instruments (WOMAC, range 0-100, higher scores indicate worse pain, stiffness and functional limitations)

Follow-up: 24-87 months

The mean WOMAC total score in the cruciate-sacrifice group was 18.2 points(± SE 1.5)

The mean WOMAC total score in the cruciate-retention group was 1.60 lower

(1.32 lower to 4.50 higher)

 

Total No. of patients: 415

(23%)

Total No. of knees: 445

(20%)

3 studies

(18%)

⊕⊕⊝⊝
low 1, 2

Absolute difference: 1.60 lower

(1.32 lower to 4.50 higher)

Relative percent change: -8.8% (7.3% lower to 24.7% higher)

Not statistically significant.

Global assessment (patient)See commentSee commentNot estimable--See commentNo data in studies comparing ligament resection and sacrifice using similar arthroplasty designs

Complications

Follow-up: 8-87 months5

See commentSee commentNot estimable

Total No. of patients: 878

(49%)

Total No. of knees: 1,220

(55%)

8 studies

(47%)

See commentDue to the very diverse way of reporting and defining complications combining data for quantitative analysis was not possible3,4

Re-operation rate (not involving implant change, short- and long-term)

Follow-up: 24 months

See commentSee commentNot estimable

Total No. of patients: 40

(2%)

1 study

(6%)

See comment Catani 2004 reported 4 re-operations; 3 patella luxations (2 in cruciate-sacrificing, 1 in cruciate-retention group) and 1 surgical manipulation due to lack of range of motion (in the cruciate-retention group)
CI: Confidence interval. KSS: Knee Society Score, WOMAC: Western Ontaria and McMasters Universities Osteoarthritis Index. ROM range of motion NA: not applicable
GRADE Working Group grades of evidence
High quality: Further research is very unlikely to change our confidence in the estimate of effect.
Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate.
Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate.
Very low quality: We are very uncertain about the estimate.

Background

Description of the condition

Osteoarthritis is a degenerative joint disease leading to degradation of articular cartilage and subchondral bone. Clinically, patients with knee osteoarthritis present in general with disabling knee pain and impaired knee function. At some point during the disease the only remaining treatment is surgery with a total knee arthroplasty.

Description of the intervention

A total knee arthroplasty is the resurfacing of the joint articulating surfaces. During total knee arthroplasty surgery several structures involved in the knee joint are either retained (for example the posterior cruciate ligament), replaced by artificial structures (for example patella resurfacing), or discarded (for example the anterior cruciate ligament and possibly the posterior cruciate ligament). The distal femur and proximal tibia are cut and replaced by a femoral and a tibial component. Between these components a polyethylene insert is placed. See Figure total knee arthroplasty components (Figure 1).

Figure 1.

Bicondylar ligament cruciate retaining balancing total knee arthroplasty with rotating platform (balanSys®, Mathys Ltd., Bettlach, Switzerland) Hirschmann et al. BMC Musculoskeletal Disorders 2010 11:167   doi:10.1186/1471-2474-11-167
Download authors' original image

For total knee arthroplasty it is desirable to reproduce the natural movements of the knee while maintaining stability from extension to flexion. In patients in whom the posterior cruciate ligament can be retained, this ligament can provide these requirements (Lombardi 2001; Mihalko 1999). Moreover, the posterior cruciate ligament is supposed to have different types of mechanoreceptors detecting joint position (proprioception) and joint motion (kinaesthesia) (Hogervorst 1998; Nelissen 2001; Swanik 2004). However, the structural integrity of the posterior cruciate ligament of an osteoarthritic knee may be lost due to mucoid degeneration (Nelissen 2001). When the posterior cruciate ligament is retained in total knee arthroplasty, some studies have shown a lack of posterior femoro-tibial translation (for example the naturally occurring movement of the distal femur on the tibia, also known as rollback) with knee flexion (Dennis 1998; Mahoney 1994). This is thought to be attributable to inadequate balancing of the posterior cruciate ligament in flexion during surgery (Emodi 1999; Most 2003; Nozaki 2002). Balancing of the posterior cruciate ligament consists of choosing the insert thickness and component sizes in a way that the posterior cruciate ligament is adequately tensioned in flexion but relaxed in extension. When posterior cruciate ligament balancing has not been performed adequately, the patient might have a suboptimal total knee arthroplasty, which often produces pain (Pagnano 1998). If the posterior cruciate ligament is too loose, the patient might present with instability (Pagnano 1998; Waslewski 1998). If the posterior cruciate ligament is too tight, the patient suffers from limited flexion and the polyethylene insert is subjected to high stresses and wear (Migaud 2003; Pagnano 1998). A release of the posterior cruciate ligament can be used in cases with a tight ligament and difficulty to perform knee flexion during the procedure.

In many instances, however, the posterior cruciate ligament is sacrificed in the surgical procedure and another arthroplasty design is used. Sacrifice of the posterior cruciate ligament results in an increase in the flexion gap (the flexion gap is the gap between the cut posterior parts of the distal femur and the cut proximal tibia when the knee is flexed) (Baldini 2004; Mihalko 1999). This increase is generally compensated for with thicker polyethylene inserts or larger femoral components. Sacrificing the posterior cruciate ligament leads to an increase in the extension gap as well (the extension gap is the gap between the cut distal femur and the cut proximal tibia when the knee is in extension) (Baldini 2004). The size of these gaps has to be in such a way that the ligaments in and around the knee joint are balanced in order to achieve stability after placement of the arthroplasty. Several adjustments in total knee arthroplasty design exist to compensate for the absence of the posterior cruciate ligament. The posterior stabilised design is most commonly used. This design has a cam post mechanism to substitute for the function of the posterior cruciate ligament and permits rollback of the femoral component on the tibial component during flexion. Other knee systems use deep dish inserts with a high anterior rim as a brake against posterior subluxation of the tibia.

Factors influencing the choice of sacrifice or retention of the posterior cruciate ligament are the degenerative status of the ligament, knee deformities, the type of implant used, or the personal preference of the surgeon. Lombardi 2001 proposed a decision tree based upon the patient's history, the clinical examination, and the intraoperative findings (Lombardi 2001).

Why it is important to do this review

Randomised studies comparing posterior cruciate ligament retention with sacrifice have been conducted from the early 90s up to now (Seon 2011; Shoji 1994). In 2005, when the original Cochrane systematic review on this topic was published, these studies combined in a meta-analysis could not find a clear difference between the two treatments. It was impossible to give clear advice on whether to retain or to sacrifice the posterior cruciate ligament (Jacobs 2005). In this extensive update the question remains whether the study results allow for pooling and whether the pooled results favour retention or sacrifice of the posterior cruciate ligament.

Objectives

To assess the range of motion, pain, clinical and radiological outcomes in patients with retention versus sacrifice of the posterior cruciate ligament in total knee arthroplasty for the treatment of osteoarthritis.

Methods

Criteria for considering studies for this review

Types of studies

Randomised and quasi-randomised controlled trials were included. Quasi-randomised studies use alternating sequences for randomisation (that is odd or even chart numbers, date of hospital admission, etc.) Non-randomised clinical trials and historically controlled studies were excluded.

Types of participants

Studies were included when dealing with patients with osteoarthritis. Studies which included a wider range of indications were excluded if the proportion of patients with osteoarthritis was lower than 95% of the total group or when the subgroups were poorly described with separate results.

Types of interventions

Studies were included if total knee arthroplasty with retention of the posterior cruciate ligament was compared to sacrifice of the posterior cruciate ligament. Procedures with sacrifice of the posterior cruciate ligament were considered when the same arthroplasty design or when a posterior cruciate ligament substituting design was used.

Types of outcome measures

Major outcomes
  • Performance outcome: range of motion (flexion, extension)

  • Knee pain (i.e. as measured by a Visual Analogue Scale (VAS), Knee Society Score pain subscale, etc.)

  • Implant survival rate (revision surgery)

  • Validated clinical and functional questionnaire scores (i.e. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC))

  • Patient satisfaction

  • Complications

  • Re-operations other than revision surgery (e.g. manipulation because of impaired knee function)

Minor outcomes
  • Specific evaluation of daily tasks (i.e. walking or stair climbing ability, rising from a chair)

  • Less validated clinical and functional questionnaire scores (i.e. Knee Society score)

  • Radiological outcomes (i.e. Radio Stereotactic Analysis (RSA)

  • Gait analysis parameters

Search methods for identification of studies

Electronic searches

We conducted a sensitive search in order to retrieve all available literature. In consultation with an experienced librarian of the medical scientific library of the Leiden University Medical Center, we searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (PubMed), EMBASE, Web of Science, CINAHL, Academic Search Premier, Current Contents Connect and Science Direct. All databases were searched up to 6 December 2012 using an adopted syntax for every single database. The search syntax for the different databases is presented in Appendix 1. No restrictions or limits were formulated.

Searching other resources

A final check that no relevant articles were missed was carried out by screening the references from the articles and by performing citation tracking on the articles that were selected. To identify ongoing trials comparing retention with sacrifice of the posterior cruciate ligament we checked the online trial registries via the portal of the World Health Organization (www.who.int/trialsearch ).

Data collection and analysis

Selection of studies

Articles were selected in two steps. Studies were excluded when it was apparent from the title or the abstract that the study did not meet all of the following criteria.

  • The intervention evaluated in the trials had to be primary total knee arthroplasty (excluding post-patellectomy and post-osteotomy studies), comparing one treatment in which the posterior cruciate ligament was retained against one in which it was sacrificed. Procedures with sacrifice of the posterior cruciate ligament were considered when the same prosthesis design was used as for the retention group, or when a posterior cruciate ligament substituting design was used (e.g. posterior stabilised or a deep dish insert).

  • The indication for total knee arthroplasty had to be osteoarthritis. Studies which included a wider range of indications were excluded if the proportion of patients with osteoarthritis was lower than 95% of the group.

  • Minimal follow-up had to be 12 months.

  • Studies had to be randomised or quasi-randomised controlled trials.

In the first step only the titles and abstracts were screened. In the second step, articles which passed the first step were retrieved in full and evaluated against the inclusion and exclusion criteria.

Data extraction and management

One review author (WV) conducted the literature search and retrieved the references to be evaluated. Two review authors (WV, LB) independently selected the trials to be included in the review. Disagreements were resolved by consensus. When no consensus could be reached, a third review author (WJ) was available for the decisive vote. A pre-developed and tested data extraction form was used to extract data from the selected studies. Items collected were: study design features, population data, statistical analysis techniques, intervention characteristics, and all reported outcome parameters including results. All data was entered into Review Manager 5.1 (Review Manager 2011). When a selected article was written in a foreign language, the data extraction form was sent to a translator via the Cochrane Musculoskeletal group. A second form was used to assess the risk of bias (see below) and the clinical relevance of the selected studies.

Assessment of risk of bias in included studies

Selected studies were closely examined by two review authors working independently (WV, LB). Risk of bias was assessed according to the recommendations of The Cochrane Collaboration in risk of bias tables (Higgins 2011). To detect selection bias, performance bias and attrition bias, several items were evaluated in all selected studies. The risk of selection bias was judged by assessing how the randomisation sequence was generated and by assessing the way the allocation of treatment was concealed. Risk of performance and detection bias was judged by evaluating the blinding (of personnel, patients and outcome assessors) in the studies. The risk of attrition bias was assessed by judging the completeness of the data, including the follow-up rates. Finally, the risk of reporting bias was assessed by judging if all (relevant) outcome measurements were reported. The possible judgments that could be made were low risk of bias, high risk of bias and unclear risk of bias.

Measures of treatment effect

Continuous data were entered as means and standard deviations, dichotomous outcomes as number of events. In the absence of significant heterogeneity, and given sufficient included trials, results were combined using mean differences for continuous data and risk ratios for dichotomous data.

Unit of analysis issues

Special issues in the analysis of studies with non-standard (randomised controlled trial) designs (for example cluster-randomised trials) were identified. A specific issue for studies on knee replacement surgery is the possibility to perform surgery bilaterally: allocating one knee to posterior cruciate ligament retention automatically allocates ligament sacrifice to the other contralateral knee.

Dealing with missing data

Standard deviations were used when available. When not provided, standard deviations were imputed from comparable studies or from the original scores (for example confidence intervals) when calculating change scores (Higgins 2011).

Assessment of heterogeneity

Heterogeneity was first assessed by visual inspection of the forest plots. Furthermore, it was investigated with the I2 statistic and if significant (P < 0.10 using the Chi2 statistic) the source of heterogeneity was investigated by doing a sensitivity analysis and considering clinical reasons for potential clinical heterogeneity. I2 values of 30% to 50% were considered to represent moderate heterogeneity; from 50% to 80% were considered to represent substantial heterogeneity and above 80% considerable heterogeneity (Higgins 2011).

Assessment of reporting biases

In order to evaluate the risk of publication bias we checked the online trial registries via the portal of the World Health Organization (www.who.int/trialsearch ). When studies were tagged as 'stopped' (for example not ongoing) and were not published in an article, the investigator of the study was contacted and the reason why the study was not published was identified, when possible.

Data synthesis

Statistical analyses were conducted using RevMan 5.1. The outcomes specified in the protocol were included in the analysis. A random-effects model was used for all analyses in this review (Fleiss 1993).

Subgroup analysis and investigation of heterogeneity

Besides the general comparison of total knee arthroplasties with and without sacrifice of the posterior cruciate ligament, several subgroup analyses were performed. First, as in the original Cochrane review, studies evaluating the effect of posterior cruciate ligament retention and sacrifice using the same design total knee arthroplasty (the posterior cruciate ligament retaining design) were considered in a subgroup analysis. Secondly, the studies evaluating the effect of posterior cruciate ligament retention and sacrifice comparing a posterior cruciate ligament retaining arthroplasty design with a posterior stabilised posterior ligament sacrificing design were considered in a subgroup analysis. When other design modifications than posterior stabilisation were studied, these were considered in separate subgroup analyses.

Sensitivity analysis

When it was unclear if findings in the meta-analysis were robust to the decisions made in the process of obtaining them, this was tested in a sensitivity analysis. For example, when data for a specific outcome measure were not adequately reported the analysis was performed with and without inputed outcome values. Findings were considered 'robust' when they did not change significantly. Moreover, outcomes of the meta-analyses were compared with the pooled outcomes from the studies with the lowest risk of bias.

Quality of evidence and summary of findings tables

For the outcome measures range of motion, flexion angle and knee pain, the primary outcome measures, beneficial effects were evaluated. To evaluate harmful effect differences between the two treatment groups we evaluated the occurrence of complications. Results were presented in 'summary of findings' tables. As prescribed by The Cochrane Collaboration, a quality of evidence assessment was performed using the GRADE approach (with GRADEpro software (version 3.6)).

The different grades of evidence according to the GRADE working group are as follows.

  • High quality: further research is very unlikely to change confidence in the estimate of effect.

  • Moderate quality: further research is likely to have an important impact on confidence in the estimate of the effect, and may change the effect.

  • Low quality: further research is very likely to have an important impact on confidence in the estimate of the effect, and is likely to change the effect.

  • Very low quality: the effect estimate is very uncertain.

Results

Description of studies

Results of the search

For this update, a total of 2129 unique references were identified (Figure 2, PRISMA flowchart). The search in MEDLINE (PubMed) resulted in 858 references. Furthermore, EMBASE yielded 543 unique references, Web of Science 299, Current Contents Connect 19, CENTRAL 72, CINAHL 215, Academic Search Premier 26 and Science Direct 97 unique references. After the first step of selection, 55 articles were selected for the second step. After applying the inclusion and exclusion criteria to the full text 18 papers remained. Citation tracking did not result in any extra references.

Figure 2.

Study flow diagram (PRISMA).

The article of Victor 2005 described a population that was also part of the study population of Harato 2008. The data from both articles were used only once.

Included studies

Ultimately 17 studies (with 1810 patients and 2206 knees), described in 18 articles, were considered for analysis (Aglietti 2005; Catani 2004; Chaudhary 2008; Clark 2001; de Andrade 2009; Harato 2008; Kim 2009; Maruyama 2004; Matsumoto 2012; Misra 2003; Roh 2012; Seon 2011; Shoji 1994; Straw 2003; Tanzer 2002; Victor 2005; Wang 2004; Yagishita 2012). Ten studies were new compared to the original Cochrane review. The article of de Andrade et al (de Andrade 2009) was written in Portuguese and data were extracted by a translator from the Cochrane Musculoskeletal Group.

Interventions

In 12 studies the comparison between the two treatment arms was posterior cruciate retention with a cruciate retaining design versus sacrifice using a posterior stabilised design (Aglietti 2005: LPS/MBK; Catani 2004: Optetrak; Chaudhary 2008: SCORPIO; Clark 2001: AMK; de Andrade 2009: NexGen; Harato 2008: Genesis II; Kim 2009: NexGen; Maruyama 2004: PFC; Matsumoto 2012: NexGen; Seon 2011: NexGen; Tanzer 2002: NexGen; Yagishita 2012: NexGen). In three studies the same (cruciate-retaining) arthroplasty design was used for both groups (Misra 2003: PFC; Roh 2012: E-motion; Shoji 1994: Total Condylar Modifier). One study used all three treatments (that is cruciate-retaining design with ligament retention and with ligament sacrifice and a posterior stabilised design (Straw 2003: Genesis I). Finally, one study did not clearly report the design of the arthroplasty (Wang 2004).

Duration of follow-up in the included studies

Aglietti 2005 had a mean follow-up of 36 months (range 30 to 48 months). Catani 2004 had a 24 months follow-up; no range was reported. Chaudhary 2008 had a mean follow-up of 22.7 months (± 5.2 months). Follow-up in the study from Clark 2001 ranged from 12 to 36 months; no mean follow-up was reported. de Andrade 2009 had a mean follow-up of 15.8 months (± 3.8 months). Harato 2008 had a mean follow-up of 64.8 months (range 60 to 87.6 months) for the cruciate-retention group and a mean follow-up of 67.2 months (range 60 to 87.6 months) for the cruciate-sacrificing group. Kim 2009 had a mean follow-up of 27.6 months (range 24 to 36 months). Maruyama 2004 had a mean follow-up of 31.7 months (range 24 to 53 months) for the cruciate-retention group and a mean follow-up of 30.6 (range 24 to 38 months) for the cruciate-sacrificing group. Matsumoto 2012 had a mean follow-up of 71.9 months (range 61 to 83 months) for the cruciate-retention group and a mean follow-up of 70.2 months (range 63 to 87 months) for the cruciate-sacrificing group. Misra 2003 had a mean follow-up of 57 months; no range was reported. Roh 2012 had a mean follow-up of 27.3 months (range 24 to 28 months) for the cruciate-retention group and a mean follow-up of 32.2 months (range 24 to 37 months) for the cruciate-sacrificing group. Seon 2011 had a mean follow-up of 26.1 months (± 1.7) for the cruciate-retention group and a mean follow-up of 28.4 months (± 2.1) for the cruciate-sacrificing group. Shoji 1994 had a mean follow-up of 38.4 months (range 30 to 54 months). Straw 2003 had a mean follow-up of 42 months (range 12 to 78 months). Tanzer 2002 had a mean follow-up of 24 months; no range was reported. Wang 2004 had a mean follow-up of 42 months (range 24 to 66 months). Yagishita 2012 had a mean follow-up of 60 months (range 36 to 73 months). See Characteristics of included studies.

Sex and age (patient characteristics)

The mean age in Aglietti 2005 et al was 71 years in the cruciate-retention group (86% female patients) and 69.5 years in the cruciate-sacrificing group (81% female patients). The mean age in Catani 2004 et al was 70 ± 6.0 years in the cruciate-retention group (65% female patients) and 71 ± 7.0 years in the cruciate-sacrificing group (75% female patients). The mean age in Chaudhary 2008 et al was 69.2 ± 9.1 years in the cruciate-retention group (53% female patients) and 70.2 ± 8.4 years in the cruciate-sacrificing group (45% female patients). The mean age in Clark 2001 et al was 71.8 ± 12.2 years in the cruciate-retention group (sex of the patients not reported) and 71.2 ± 13.6 years in the cruciate-sacrificing group. The mean age in de Andrade 2009 et al was 66.3 years (range 41 to 78 years) overall; 74% pf the patients were female. The mean age in Harato 2008 et al was 68.3 years (range 49 to 89 years) in the cruciate-retention group (34% female patients) and 66.0 years (range 44 to 83 years) in the cruciate-sacrificing group (34% female patients). The mean age in Kim 2009 et al was 71.6 ± 6.0 years overall; in the cruciate-retention group (86% female patients) and 69.5 years in the cruciate-sacrificing group (81% female patients). The mean age in Maruyama 2004 et al was 74.3 years (range 65 to 84 years) overall; 60% of the patients were female. The mean age in Matsumoto 2012 et al was 73.5 ± 1.3 years in the cruciate-retention group (100% female patients) and 74.4 ± 0.9 years in the cruciate-sacrificing group (100% female patients). The mean age in Misra 2003 et al was 66.8 years (range 55 to 83 years) in the cruciate-retention group (67% female patients) and 67.2 years (range 59 to 82 years) in the cruciate-sacrificing group (59% female patients). The mean age in Roh 2012 et al was 69.8 ± 4.7 years in the cruciate-retention group (95% female patients) and 71 ± 4.9 years in the cruciate-sacrificing group (93% female patients). The mean age in Seon 2011 et al was 68.2 ± 7.0 years in the cruciate-retention group (91% female patients overall in the study) and 69.1 ± 6.7 years in the cruciate-sacrificing group. The mean age in Shoji 1994 et al was not reported nor was the sex distribution of the patients. The mean age in Straw 2003 et al was 72.6 years in the cruciate-retention group, 72.6 years in the posterior stabilised group and 74.1 years in the cruciate-sacrificing group. The mean age in Tanzer 2002 et al was 68 years (range 51 to 86 years) in the cruciate-retention group (75% female patients) and 66 years (range 52 to 77 years) in the cruciate-sacrificing group (80% female patients). The mean age in Wang 2004 et al was 54.5 years (range 31 to 69 years) in the cruciate-retention group (80% female patients) and 55 years (range 20 to 83 years) in the cruciate-sacrificing group (80% female patients). The mean age in Yagishita 2012 et al was 74.3 ± 7.2 years overall; 86% of the patients were female. See Characteristics of included studies.

Categorisation

The comparisons made in the trials could be divided into several distinct comparisons based on the outcome of range of motion. One was posterior cruciate ligament retention versus sacrifice with a posterior stabilised total knee arthroplasty design. Another comparison was made between posterior cruciate ligament retention versus sacrifice using the same arthroplasty design (see analysis section).

Two studies (Misra 2003; Shoji 1994), identified in the original review, and one new study (Roh 2012) compared posterior cruciate ligament retention and sacrifice using the same arthroplasty design (for example a posterior cruciate retaining design without a substitution of the resected ligament). When a specific posterior cruciate ligament substituting design was used, a posterior cruciate ligament retaining design was compared with a posterior stabilised design in all selected studies.

For details of the included studies see the Characteristics of included studies table.

Outcomes

All studies used a clinical rating scale, either well validated (that is WOMAC) or less well validated (that is Knee Society score or Hospital for Special Surgery score), and reported range of motion or flexion measurements.

Sample size

Eight studies (Aglietti 2005; Clark 2001; Harato 2008; Kim 2009; Misra 2003; Seon 2011; Straw 2003; Wang 2004) had group sizes of more than 50. Chaudhary et al compared 51 patients in which the posterior cruciate ligament was retained to 49 patients in which it was sacrificed (Chaudhary 2008).

Excluded studies

One study from the original Cochrane review (Jacobs 2005) was excluded from this update (Swanik 2004). This study reported results with a mean follow-up of 7.6 months. The protocol stated that follow-up had to be at least 12 months.

Most excluded studies were classified as non-randomised studies after reading the full text articles. Proceeding communications and abstracts of studies presented at international congresses were evaluated (Husain 1998; Matsuda 2003; MacDonald 2005; Surace 1997; Yamamoto 2003). Since methodological issues (for example randomisation technique) and outcome measures (for example mean with standard deviation) were not reported extensively enough, these studies were not included in the analyses. No additional publications were found for these studies. Ten studies were excluded for other different reasons.

For an overview of the excluded studies see the Characteristics of excluded studies table.

Risk of bias in included studies

Overall, the more recent publications had a lower risk of bias. Based on study characteristics and the risks of bias as described before, the studies of highest quality from the current selection of articles were Chaudhary (Chaudhary 2008), Kim (Kim 2009), Misra (Misra 2003) and Seon (Seon 2011).

Allocation

Four of the selected studies (24%) described how the randomisation sequence was generated (Chaudhary 2008: computer generated randomisation blocks; Harato 2008: randomisation blocks, stratified per centre; Misra 2003: random numbers table; Roh 2012: permuted block randomisation). The other 13 studies (76%) did not describe randomisation sequence generation (see Figure 3 and Figure 4). Concealment of allocation was performed using sealed or opaque envelopes, or both, as reported in five studies (29%) (Chaudhary 2008; Harato 2008; Kim 2009; Matsumoto 2012; Seon 2011). The other 12 studies (71%) did not mention concealment of allocation (see Figure 3 and Figure 4). Three studies used 'quasi-randomisation': Aglietti 2005 based treatment choice on odd or even patient numbers; Maruyama 2004 used alternating sequences; and Wang 2004 used hospital admission moment to base treatment on (see Figure 3 and Figure 4).

Figure 3.

Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

Figure 4.

Risk of bias summary: review authors' judgements about each risk of bias item for each included study.

Blinding

Blinding of participants and personnel was not described in eight studies (47%) (Catani 2004; Clark 2001; Harato 2008; Maruyama 2004; Roh 2012; Shoji 1994; Wang 2004; Yagishita 2012). Seon et al mentioned explicitly that no blinding was applied (Seon 2011). The other eight studies (47%) described only blinding of the outcome assessor (see Figure 3 and Figure 4).

Incomplete outcome data

The follow-up rate was described by all studies, ranging from 0% lost to follow-up (Catani 2004; de Andrade 2009; Maruyama 2004; Shoji 1994; Tanzer 2002; Yagishita 2012) to 22% lost to follow-up (Chaudhary 2008) (see Figure 3 and Figure 4).

Selective reporting

It seemed that 15 studies (88%) reported all outcome measures that were studied. Of these, Kim 2009 reported some outcomes (WOMAC and radiological results) in a digital appendix. Clark 2001 and de Andrade 2009 reported only the total Knee Society Score. It is more usual to report the clinical and functional score separately because this gives more insight into the nature of the possible differences between groups.

No studies were identified from the trial registries that were not still ongoing.

Clinical relevance

Clinical relevance is assessed in the table 'Assessment of clinical relevance' (Table 1). Most notable is that effect sizes of both the posterior cruciate ligament retaining and posterior cruciate ligament sacrificing groups reported in the studies were clinically not relevant in almost all of the studies.

Table 1. Assessment of clinical relevance
StudyDescription patientsIntervention describedOutcome measuresEffect size
 Are the patients described in detail so that you can decide whether they are comparable to those that you see in your practice?Are the interventions and treatment settings described well enough so that you can provide the same for your patients?Were all clinically relevant outcomes measured and reported?Is the size of the effect clinically important?

Aglietti

2004

NoYesYesNo

Catani

2004

NoNoNoYes
Chaudhary 2008YesYesYesNo

Clark

2001

UnsureYesNoNo
de Andrade 2009UnsureUnsureNoNo

Harato

2008

UnsureYesYesNo

Kim

2009

YesYesYesNo

Maruyama

2004

YesYesYesNo

Matsumoto

2012

YesUnsureYesNo

Misra

2003

NoNoNoNo

Roh

2012

YesYesYesNo

Seon

2011

YesUnsureYesYes

Shoji

1994

NoNoNoNo

Straw

2003

NoUnsureNoNo

Tanzer

2002

YesYesNoNo

Wang

2004

YesNoYesNo
Yagishita 2011YesYesYesNo

Effects of interventions

See: Summary of findings for the main comparison Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs); Summary of findings 2 Posterior cruciate ligament retention versus sacrifice (using the same arthroplasty design); Summary of findings 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice

Forest plots are displayed in the 'Data collection and analysis' section. Furthermore, an overview is given in Summary of findings for the main comparison, Summary of findings 2 and Summary of findings 3.

Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs)

These analyses included posterior cruciate retaining implant designs (sometimes used where the posterior cruciate ligament was sacrificed as well) and posterior stabilised posterior cruciate sacrificing designs. These were all studied implants included in this review.

Performance based outcome: range of motion, flexion and extension angle

Range of motion (reported in 65% of the studies, analysed on 62% of all potential patients and 65% of all potential knees) showed a mean difference of 2.4 ° (95% CI 0.13 to 4.61; P = 0.04) favouring posterior cruciate ligament sacrifice (118.3 ° versus 115.9 °). The results were heterogeneous (I2 = 60%, P = 0.006). In particular, the results of Catani 2004 were very different compared to the other studies; these results indicated a large 17 ° higher flexion angle in favour of sacrifice of the posterior cruciate ligament.

The flexion angle showed a mean difference of 1.5 ° (119.8 ° versus 118.3 °) in favour of posterior cruciate ligament sacrifice (95% CI 0.24 to 3.15; P = 0.09). The results were homogeneous (I2 = 6%, P = 0.39).

Result for the extension angle were heterogeneous (I2 = 88%, P < 0.001) and showed a statistically non-significant difference of 0.36 ° (95% CI -0.63 to 1.36).

Knee pain

Two studies reported outcomes on the VAS for pain (Aglietti 2005; Yagishita 2012). The mean difference was 1.50 points (95% CI -1.84 to 4.84; P = 0.38) in favour of ligament retention. This result was homogeneous (I2 = 0%, P = 0.58). There was also no difference between knee pain, as measured with the Knee Society pain score (zero is no pain, 50 is maximal pain). The mean difference was 0.02 points (95% CI -1.43 to 1.38; P = 0.97). However, this result was considered heterogeneous (I2 = 71%, P = 0.02). This result was based on 36% of all patients, 46% of all knees, and data were reported in 24% of all included studies.

Implant survival rate

Several studies reported the survival rate of the arthroplasties. Aglietti 2005 reported one case of revision due to septic loosening in the cruciate-sacrificing group. Chaudhary 2008 reported one revision in the cruciate-retention group, Harato 2008 reported one revision in the cruciate-retention group and three in the sacrifice group. Misra 2003 reported two revisions in the cruciate-retention group. Kim 2009, Yagishita 2012 and Tanzer 2002 specifically reported that no revision surgery had occurred during their follow-up.

Validated clinical scoring systems

A validated scoring system, the WOMAC total score, was used in four studies (24% of included studies with data on 28% of all patients and 24% of all knees) (Clark 2001; Harato 2008; Roh 2012; Seon 2011). There was a 0.78 (95% CI -1.51 to 3.07; P = 0.50) points difference between posterior cruciate ligament retention and sacrifice in favour of the posterior cruciate sacrifice (sacrifice versus retention: 15.7 versus 16.4 points). This difference was not statistically significant (P = 0.57) and was homogeneous (I2 = 0, P = 0.69). No other validated scoring systems (that is Knee injury and Osteoarthritis Outcome Score (KOOS), Oxford Knee Score) were available for pooling.

Patient satisfaction

Only Misra 2003 (one study, 6% of all included studies) asked patients to grade their satisfaction, on a scale from 0 to 10 with 10 being completely satisfied: cruciate-sacrifice scored 7.9 and cruciate-retention 7.7. This difference was not statistically significant.

Complications

Complications were reported in 11 studies (65% of all included studies, reporting on 69% of all patients and 74% of all knees). Complications are listed in Table 2. Complications occurred with equal frequency in the two treatment groups. Reported complications ranged from anterior knee pain (10 patients) and limited range of motion (14 patients) a few weeks after surgery to septic or aseptic loosening (4 and 5 patients respectively). The latter is a serious complication, also occurring equally often in the two treatment groups.

Table 2. Complications
StudyComplications posterior cruciate ligament retentionComplications posterior cruciate ligament sacrifice

Aglietti

2004

None1 Septic loosening after 2 years requiring 2-stage revision surgery

Catani

2004

1 Anterior knee pain; treated: lateral release and patella resurfacing,

1 Limited range of motion; treated: surgical manipulation

2 Anterior knee pain; treated: lateral release and patella resurfacing

Chaudhary

2008

1 Deep infection1 Limited range of motion (poor flexion); treated: surgical manipulation

Clark

2001

Not reportedNot reported

de Andrade

2009

Not reportedNot reported

Harato

2008

7 Stiff knee (<90 degrees flexion), 5 severe/moderate knee pain, 1 infection

2 Hemoarthrosis

1 Deep venous thrombosis, 3 infection, 1 stiff knee (<90 degrees flexion)

2 Severe/moderate knee pain

Kim

2009

2 Femoral notching, 1 superficial wound infection3 Femoral notching, 1 superficial wound infection

Maruyama

2004

NoneNone

Matsumoto

2012

None1 Deep venous thrombosis

Misra

2003

3 Instability, 1 infection, 2 aseptic loosening, 2 stiffness (<30 degrees flexion)

3 Instability, 3 aseptic loosening, 2 stiffness (<30 degrees flexion),

1 Reflex sympathetic dystrophy

Roh

2012

2 posterior cruciate laxity

1 posterior cruciate tightness

None

Seon

2011

Not reportedNot reported

Shoji

1994

Not reportedNot reported

Straw

2003

Not reportedNot reported

Tanzer

2002

Not reportedNot reported

Wang

2004

Not specified per treatment group:

3 deaths unrelated to the knee surgery, 3 deep wound infections, 1 above the knee amputation due to diabetic gangrene, 1 cerebral vascular accident, 1 Parkinsons disease, 1 colon cancer

Yagishita

2011

None1 Deep venous thrombosis
Other endpoints

The Knee Society functional score showed a statistically significant 2.3 points higher score (81.3 versus 79.0 points) in the posterior cruciate ligament sacrificed groups (95% CI of the difference 0.37 to 4.26; P = 0.02). Results were homogeneous (I2= 0%, P = 0.43). This result was clinically not relevant. This score ranges from 0 to 100, 100 being optimal function.

Meta-analyses on the other outcomes, as displayed in the Data and analyses section, showed no statistically significant differences. These outcomes were: Knee Society clinical score, Hospital for Special Surgery score, Short Form (SF)-12 mental score, radiological radiolucencies, radiological femorotibial angle, radiological rollback, and radiological tibial slope.

Posterior cruciate ligament retention versus sacrifice (using the same arthroplasty design)

Posterior cruciate ligament sacrifice versus retention with the same arthroplasty design (a posterior cruciate retaining design) did not show a statistically significant difference in range of motion (mean difference 2.7 °; 95% CI -8.7 to 3.32; P = 0.38). Data were heterogeneous (I2 = 88%, P < 0.001). Range of motion was the only endpoint available for meta-analysis.

Posterior cruciate ligament retention versus posterior stabilised sacrifice

Posterior cruciate ligament sacrifice versus retention with a posterior stabilised design showed a statistically significant difference in range of motion of 3.47 ° (116.5 ° versus 120.0 °) in favour of the posterior stabilised design (95% CI 0.56 to 6.38; P = 0.02). However, data were heterogeneous (I2 = 60%, P = 0.01).
The flexion angle was 2.10 ° higher (95% CI -0.04 to 4.24; P = 0.05) in favour of the posterior stabilised design. This was a homogeneous result (I2 = 1%, P = 0.42).

The outcomes VAS pain, Knee Society pain score, WOMAC total score, Knee Society clinical and functional score, Hospital for Special Surgery score, Knee Society total score, the number of radiolucent lines, the femorotibial angles and tibial slope showed no statistically significant differences and these results were homogeneous.

The outcomes extension angle, SF-12 mental score and radiological rollback showed no statistically significant differences and these results were heterogeneous.

Discussion

Summary of main results

By thoroughly updating the original review (Jacobs 2005) we were able to add 10 studies, described in 11 articles, to the analyses (Aglietti 2005; Chaudhary 2008; de Andrade 2009; Harato 2008; Kim 2009; Matsumoto 2012; Roh 2012; Seon 2011; Victor 2005; Wang 2004; Yagishita 2012). Only two outcomes differed statistically when all selected studies reporting similar outcomes were pooled. The range of motion was 2.4 ° higher and the functional Knee Society score was 2.3 points higher in the group with sacrifice of the posterior cruciate ligament. Complications were reported in 11 studies (Aglietti 2005; Catani 2004; Chaudhary 2008; Harato 2008; Kim 2009; Maruyama 2004; Matsumoto 2012; Misra 2003; Roh 2012; Wang 2004; Yagishita 2012). Complications varied from anterior knee pain and femoral notching to deep infection. Most complications occurred equally frequently in the posterior cruciate ligament sacrificing and retaining groups (Table 2). A remarkable finding in Harato 2008 was that the posterior cruciate ligament retaining group showed seven cases (6.3%) of a stiff knee, defined as < 90 ° of flexion, compared to one case (0.9%) in the posterior cruciate ligament sacrificing group.

The meta-analyses showed statistically significant differences in range of motion and in the Knee Society functional score. Although the evidence originates from a meta-analysis of more than one randomised controlled trial, one should be aware that the effect is still unstable and sensitive to the inclusion of new studies. Moreover, the mean difference in range of motion of 2.4 ° and in mean Knee Society functional score of 2.3 points are considered clinically not relevant (Pijls 2011). The table 'Assessment of clinical relevance' (Table 1) shows that most reported outcomes are not clinically relevant. The original review also showed a statistically significant mean difference in the Hospital for Special Surgery score of 1.6 points (P = 0.03) (Jacobs 2005) in favour of posterior cruciate ligament sacrifice arthroplasty. This difference, small and clinically not relevant, has disappeared in this review.

In order to have an impression of the difference in pain experienced between both groups we extracted data on pain from all studies. Four studies reported data on pain (Harato 2008; Kim 2009; Wang 2004; Yagishita 2012). All four presented the pain score as derived from the Knee Society Knee score. No study showed different scores per answer of the Knee score so it is not entirely clear how these pain scores were derived. Two studies used the VAS to evaluate the pain experienced by patients yielding no differences between retention or sacrifice of the posterior cruciate ligament (Aglietti 2005; Yagishita 2012).

The quality of the evidence, graded with the GRADE approach, ranged from moderate to low (Summary of findings for the main comparison; Summary of findings 2; Summary of findings 3). No harmful outcomes were presented in the summary of findings tables in this review due to the absence of reporting of sufficient data.

Overall completeness and applicability of evidence

Because of our broad and thorough search we were able to find 10 additional studies to the previous review, increasing completeness of the evidence. Overall, outcome measures studied in the selected studies give solid indications on the clinical, functional and radiological features one might be interested in after total knee arthoplasty. Unfortunately, patient-oriented outcomes such as patient satisfaction were hardly ever studied. An exception is Misra 2003, who asked patients to grade their satisfaction on a scale from one to 10.

Despite the fact that randomised controlled trials are described as providing the least biased evidence, the mean survival rate of total knee arthroplasty cannot be easily investigated by randomised controlled trials. Long term follow-up evaluations in observational cohort studies are valuable alternatives. A survivorship analysis report on a large cohort of 11,606 total knee arthroplasties showed a mean survival rate at 10 years after surgery of 91% (95% CI 90 to 92) in the posterior cruciate ligament retention group and 76% (95% CI 62 to 86) in the posterior cruciate ligament sacrificing posterior stabilised group (Rand 2003). Abdel et al found similar results (Abdel 2011).

In the more recent years, the high demands in performance of total knee arthroplasty in certain ethnic (for example squatting position) and religious (for example prayer position) groups as well as in younger patients who require greater magnitudes of knee flexion has led to the development of newer implants. Together with the continuing process of optimising stability and kinematics in total knee arthroplasty, high flex posterior stabilised and bi-cruciate stabilising designs were introduced. Long term follow-up studies have yet to prove whether those implants indeed show improved results compared to the more established design types. In this review, Kim 2009, Seon 2011 and Yagishita 2012 studied high flexion total knee arthroplasties.

Quality of the evidence

In the original Cochrane review, the quality of the included studies was assessed using the van Tulder and Jadad checklist (Jacobs 2005). Catani (Catani 2004), Misra (Misra 2003) and Tanzer (Tanzer 2002) were regarded as high quality studies. However, The Cochrane Collaboration nowadays discourages the use of scales assessing the quality (Higgins 2011). To assess quality and risk of bias, risk of bias tables were used as advocated by The Cochrane Collaboration. Several items were evaluated, first the method of generation of randomisation sequence. This should be based on chance and should be reported clearly to avoid doubt about bias. Together with the method of concealment of treatment allocation these items indicate the risk of selection bias. Treatment allocation has to be completely at random; knowledge of the next allocation by the care provider could result in an 'awkward' patient either being at risk of being illegally excluded from the trial or of being assigned to the other treatment group. This will lead to an overestimation of the treatment effect (Wood 2008). A valid randomisation technique is applied just before the treatments are given, thus ensuring unpredictable allocation. There are several techniques to keep the allocation unpredictable, such as sealed envelopes or a telephone call to a research centre for the treatment allocations. It was chosen to include quasi-randomised trials in the review as well. Quasi-randomisation is randomisation based on odd or even chart numbers, dates of birth, alternating sequences, day of hospital admission etc. The risk of selection bias in this kind of randomisation is higher compared to pure randomisation. Another item is blinding. In most surgical trials blinding of the surgeon is impossible. However, the patients and the observers measuring the endpoints can be blinded for the studied intervention. Well-blinded studies reduce risk of performance and detection bias. Furthermore, incomplete outcome data raise the possibility that the outcome is biased. When almost all anticipated outcome data are available the risk of attrition bias is low. Additionally, selection-by-indication bias was taken into account. This can only be corrected for if the degree of preoperative flexion contracture, valgus or varus deformity, is mentioned in the articles. Unfortunately the selected studies did not report these factors, except for one study that stated that a valgus or varus deformity in excess of 15 ° was an exclusion criterion (Chaudhary 2008).

The Cochrane Collaboration encourages the use of the GRADE approach (Atkins 2004). This GRADE approach defines "the quality of a body of evidence as the extent to which one can be confident that an estimate of effect or association is close to the quantity of specific interest" (Higgins 2011). Randomised controlled trials are considered as yielding high quality evidence. However, this grade can be downgraded to moderate, low or very low quality due to limitations in the design suggesting the likelihood of bias, indirectness of evidence, unexplained heterogeneity or inconsistency in the results, imprecision of the results, and a high probability of publication bias (Higgins 2011). Results were presented in the summary of findings tables. The Cochrane Collaboration encourages review authors to present the most important outcomes in these tables, including both beneficial and harmful outcomes. In this review serious adverse effects (for example serious complications) would be a harmful outcome, however the amount of data from the selected studies were not sufficient.

The quality of the evidence, graded with the GRADE approach, was low for range of motion, and moderate for the outcomes flexion angle and knee pain. In the subgroup analysis of posterior cruciate ligament retention and sacrifice with the same (cruciate-retaining) arthroplasty design the evidence was graded ‘very low’ for the outcome range of motion. In the other subgroup analyses (cruciate-retaining versus posterior stabilised) the evidence was moderate for the outcome range of motion (Summary of findings for the main comparison; Summary of findings 2; Summary of findings 3).

The risk of bias estimations are displayed for all selected studies in the 'Characteristics of included studies' risk of bias tables. The studies regarded as having the least risk of bias from the current selection of articles are Chaudhary (Chaudhary 2008), Kim (Kim 2009), and Misra (Misra 2003). Except for Misra 2003 these are newly added studies. There seems to be a positive trend towards better methodologically performed and reported studies in the more recent years. However, because of the incomplete description of the methodology of the trials it was difficult to assess whether the methodology was inaccurate or the description of the methodology was just lacking information. None of the selected studies could be judged on all four items described above. Selection bias items were not described in 53% of the articles (9/17), performance bias in 41% (7/17), and attrition bias in 24% (4/17) of the studies. The summary of findings tables show the results of the quality appraisal by the GRADE approach. All outcomes were downgraded from high quality to moderate or even low quality.

Reporting of external funding could influence the likelihood of publication of the study. From the selected studies only one industry funded study was found (Chaudhary 2008). One study reported a non-commercial grant from the National Council of Science (Wang 2004). Eight studies did not describe external funding (Aglietti 2005; Clark 2001; de Andrade 2009; Harato 2008; Maruyama 2004; Matsumoto 2012; Roh 2012; Shoji 1994). From the same study population described by Harato et al (Harato 2008) the report of Victor (Victor 2005) reported no external funding. The rest of the selected studies explicitly reported no external funding.

Potential biases in the review process

This review has several strengths and limitations. As mentioned before, randomised controlled trials are not the best studies to evaluate implant survival (for example 10 or 15 year survival) because follow-up is usually too short in trials. Since implant survival is an important outcome after total knee arthroplasty this is a limitation. Furthermore, we could not present information on patient experience and satisfaction after total knee arthroplasty because these data were not presented in the selected studies. Even in a systematic review, publication bias can never be ruled out with certainty. We applied a relatively broad search strategy in multiple databases. Nevertheless, some references could not be indexed in the databases; therefore we also used citation tracking and we checked the reference lists of the included articles. Screening the international trials registers via the portal of the World Health Organization (www.who.int/trialsearch), four trials, tagged with an ongoing status, were found (ACTRN12609000960257; ISRCTN05635855; ISRCTN82612978; van den Boom 2009). For one of these studies, the study protocol was published ahead of starting the trial (van den Boom 2009). No clinically relevant differences and only two statistically significant differences were found comparing the two groups in our meta-analyses, this might be due to a power problem. In the next update of the review these four studies can possibly overcome this problem.

This systematic review with meta-analysis was composed in accordance with the criteria of the PRISMA statement (Preferred Reporting Items for Systematic reviews and Meta-Analyses) (Liberati 2009). This is a revision and expansion of the QUORUM statement (QUality Of Reporting Of Meta-analyses). Another strength is that we applied a broad and extensive search strategy.

Agreements and disagreements with other studies or reviews

Similar to the randomised and quasi-randomised controlled trials selected in this review, other orthopaedic literature on this topic shows inconclusive results. Range of motion, for example, is the parameter most often measured. Only two randomised controlled trials (Catani 2004; Straw 2003) found a statistically significant difference, favouring posterior cruciate ligament sacrifice. One study (Stiehl 1997) found a superior range of motion for a posterior cruciate ligament retaining total knee arthroplasty and another study (Maloney 1992) for a posterior stabilised design. However, both studies showed a higher preoperative range of motion for the group with the superior results. Hirsch (Hirsch 1994) found a superior range of motion for a posterior stabilised design over posterior cruciate ligament sacrifice in a total knee arthroplasty without posterior stabilisation. Preoperative range of motion is believed to have a large influence on the postoperative results. Therefore, improvement of range of motion should be calculated and reported as well. The method of assessment of range of motion was not described in all reports. The measurement of range of motion is notoriously inaccurate if performed clinically (Kafer 2005).

Clinical rating scales are considered not very sensitive tools to evaluate the difference between two implant designs when only total scores are reported. WOMAC and KOOS scales are better validated and hence are preferred instruments for use in clinical trials. The studies in this review did not find any difference. Other non-randomised studies show the same results; several studies found no difference on the Hospital for Special Surgery score between a posterior cruciate ligament retaining and a posterior stabilised design (Becker 1991; Pereira 1998; Vinciguerra 1994).

Technically relevant outcome measures are the outcomes anterior-posterior stability and contact position. These measurements were not addressed in any of the studies. One laboratory study concludes that proper balancing is imperative to achieve proper rollback (Most 2003). De Jong et al found an average contact point between the femur and tibia at the posterior two-thirds of the anteroposterior distance of the tibia and assumed that this is also the correct contact point for a replaced cruciate retaining knee implant and a correctly balanced posterior cruciate ligament (de Jong 2010). Balancing of the posterior cruciate ligament is technically more difficult due to the oblique orientation of the posterior cruciate ligament in flexion and a strong 3 to 5 mm anterior translation of the tibia with a 2 mm increase of the insert thickness (Christen 2007; Heesterbeek 2010).

Several studies using fluoroscopy suggest that participants having a posterior stabilised total knee arthroplasty have less abnormal knee kinematics in deeper flexion and greater flexion than participants having a posterior cruciate ligament retaining total knee arthroplasty (Dennis 1998; Garling 2005; Udomkiat 2000; Victor 2005; Wolterbeek 2009; Wolterbeek 2011). As mentioned before, the posterior cruciate ligament is reported to have proprioceptive properties (Hogervorst 1998; Nelissen 2001; Swanik 2004). Another study found no difference in proprioception between a posterior cruciate ligament retaining and a posterior stabilised design (Cash 1996). Simmons 1996 found no difference in proprioception in moderate grades of osteoarthritis, but in higher osteoarthritis grades the posterior cruciate ligament retaining group performed better than the sacrificing group.

Gait analysis could provide additional but generally unvalidated results. In this review we did not find any randomised controlled trials evaluating gait analysis. Dennis et al found in two (fluoroscopic) studies that posterior cruciate ligament retaining and posterior stabilised arthroplasties have similar kinematic patterns in early flexion activities such as gait (Dennis 2003; Dennis 2004). Bolanos et al performed gait analysis on posterior cruciate ligament retaining and posterior stabilised arthroplasties and found no statistically significant differences in range of motion or knee flexion moments during a level gait (Bolanos 1998). A recent study showed no differences in gait analysis parameters between posterior cruciate ligament retention and posterior stabilised total knee arthroplasty with the ligament resected in both treatment arms (Joglekar 2012). Ishii 1998 found increased abduction and adduction and increased proximal and distal translation during gait analysis for the posterior stabilised design, which may indicate decreased stability; however the results did not differ significantly.

There are other issues to be considered in total knee replacement surgery like the choice of what kind of bearing system is to be used. Jacobs 2004(2) performed a Cochrane systematic review to answer this question, this review is currently in update phase. Another question is whether or not to use cement on the implants, and Nakama 2012 has performed a Cochrane systematic review to answer this question. We refer to these reviews for more in-depth information on these issues.

Authors' conclusions

Implications for practice

Based on this update of a Cochrane systematic review and meta-analysis, no clear and relevant differences were identified between either retention or sacrifice of the posterior cruciate ligament, or between retention and sacrifice accompanied by a posterior stabilised design. The studies found to support any conclusions on this comparison are still of limited quality. The technique of posterior cruciate ligament balancing is very demanding and complicated, and was not carefully described in the identified trials. Furthermore, the preoperative deformity of the knee might necessitate certain soft tissue releases for correct alignment, thus making it impossible to retain the posterior cruciate ligament (that is severe flexion contracture, valgus contracture). Techniques to improve balancing of the posterior cruciate ligament during total knee arthroplasty are still ongoing as this is a specific focus within total knee arthroplasty surgery. When these techniques are developed and described in sufficient detail renewed scientific experiments in patient series should be undertaken.

Implications for research

Total knee arthroplasty is a successful procedure. To improve an already successful procedure we need to look at small details. We believe that the treatment of the posterior cruciate ligament during surgery remains one of those details. Therefore, choices regarding retention or sacrifice of the posterior cruciate ligament should be thoroughly investigated in adequately and well-developed trials. The inability to apply surgeon blinding in these trials increases the need for independent and blinded outcome assessments. Also, after the surgical procedure, the patient cannot be changed to the other group and any revision implies that the treatment has been discontinued, so the quality criteria 'intention to treat' and 'compliance' should be used for cost effectiveness analysis but cannot be used for an analysis of the performance of the study. This should be taken into account. The quality of reporting of the trials is still poor; 33% to 66% of the risk of bias items were marked as 'unclear risk'. Sufficient information about the patient population was lacking in the majority of the studies. The degree of preoperative deformity was not mentioned. The selection criteria used should be given as well as the result of this selection procedure. This is essential for other clinicians to decide if the results of the trial are applicable to their own patient populations. In the field of knee surgery, the use of well-validated clinical rating scales such as the KOOS or WOMAC scale is important and they should be used more frequently, in the correct form.

Equally important is the description of the treatments applied. In the field of knee arthroplasty a few specific characteristics should be mentioned. These are the mobility of the insert (for example fixed, mobile), the status of the posterior cruciate ligament, whether either the tibial or femoral component has been cemented, the coating of the implant, the posterior tibial slope, and whether the patella has been resurfaced. The choice of the outcome parameter in a randomised trial is often of specific interest for a specific study. In studies evaluating the posterior cruciate ligament in total knee arthroplasty this should be range of motion (flexion), stability, and contact position. When more generally accepted outcome parameters are also used, the trials can be grouped together in future systematic reviews. Trials should be set up to assess the outcome parameters at uniform time intervals for all patients, before and at more than one time after the surgery. This increases the chance that identical follow-up times can be constructed from different trials. At the least, the short term outcome should be assessed at one and two years and the long term outcome at five and 10 years. It is equally important that the assessed variables are presented for the follow-up times as well for all subgroups. Besides these more technical outcome measures of total knee arthroplasty, more attention should be given to outcomes such as patient experience, quality of life and satisfaction after total knee arthroplasty.

Acknowledgements

We would like to thank JW Schoones, librarian (Walaeus Library, Leiden University Medical Center, Leiden, the Netherlands) for assisting in the searches and arranging reprints, as well as the Cochrane Musculoskeletal Group, especially Ms E Ghogomu for her help in the development of the review.

Data and analyses

Download statistical data

Comparison 1. Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs)
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Range of motion111440Mean Difference (IV, Random, 95% CI)-2.37 [-4.61, -0.13]
2 Flexion angle9915Mean Difference (IV, Random, 95% CI)-1.47 [-3.15, 0.21]
3 Extension angle7734Mean Difference (IV, Random, 95% CI)0.36 [-0.61, 1.32]
4 VAS pain2268Mean Difference (IV, Random, 95% CI)1.50 [-1.84, 4.84]
5 Knee pain (KSS pain)41004Mean Difference (IV, Random, 95% CI)0.01 [-1.40, 1.43]
6 WOMAC total4531Mean Difference (IV, Random, 95% CI)0.78 [-1.51, 3.07]
7 Knee Society Clinical score111637Mean Difference (IV, Random, 95% CI)-0.08 [-0.93, 0.77]
8 Knee Society Function Score91539Mean Difference (IV, Random, 95% CI)-2.32 [-4.26, -0.37]
9 Hospital Special Surgery Score6882Mean Difference (IV, Random, 95% CI)-0.51 [-1.55, 0.54]
10 Knee Society Score overall2213Mean Difference (IV, Random, 95% CI)-0.39 [-10.80, 10.03]
11 SF-12 mental2350Mean Difference (IV, Random, 95% CI)0.41 [-5.08, 5.89]
12 Radiological: Radiolucent lines5754Risk Ratio (M-H, Random, 95% CI)0.86 [0.68, 1.07]
13 Radiological: Femorotibial angle71170Mean Difference (IV, Random, 95% CI)0.36 [-0.08, 0.79]
14 Radiological: Rollback (in mm)2110Mean Difference (IV, Random, 95% CI)2.78 [-9.57, 15.13]
15 Radiological: Tibial slope298Mean Difference (IV, Random, 95% CI)-0.37 [-1.21, 0.48]
Analysis 1.1.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 1 Range of motion.

Analysis 1.2.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 2 Flexion angle.

Analysis 1.3.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 3 Extension angle.

Analysis 1.4.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 4 VAS pain.

Analysis 1.5.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 5 Knee pain (KSS pain).

Analysis 1.6.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 6 WOMAC total.

Analysis 1.7.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 7 Knee Society Clinical score.

Analysis 1.8.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 8 Knee Society Function Score.

Analysis 1.9.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 9 Hospital Special Surgery Score.

Analysis 1.10.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 10 Knee Society Score overall.

Analysis 1.11.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 11 SF-12 mental.

Analysis 1.12.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 12 Radiological: Radiolucent lines.

Analysis 1.13.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 13 Radiological: Femorotibial angle.

Analysis 1.14.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 14 Radiological: Rollback (in mm).

Analysis 1.15.

Comparison 1 Posterior cruciate ligament retention versus sacrifice (all types of arthroplasty designs), Outcome 15 Radiological: Tibial slope.

Comparison 2. Posterior cruciate ligament retention versus sacrifice (using the same arthroplasty design)
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Range of motion4372Mean Difference (IV, Random, 95% CI)-2.70 [-8.71, 3.32]
2 Improvement of range of motion2161Mean Difference (IV, Random, 95% CI)1.92 [-6.25, 10.08]
Analysis 2.1.

Comparison 2 Posterior cruciate ligament retention versus sacrifice (using the same arthroplasty design), Outcome 1 Range of motion.

Analysis 2.2.

Comparison 2 Posterior cruciate ligament retention versus sacrifice (using the same arthroplasty design), Outcome 2 Improvement of range of motion.

Comparison 3. Posterior cruciate ligament retention versus posterior stabilised sacrifice
Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size
1 Range of motion81193Mean Difference (IV, Random, 95% CI)-3.43 [-6.32, -0.54]
2 Flexion angle7605Mean Difference (IV, Random, 95% CI)-2.07 [-4.17, 0.04]
3 Extension angle6438Mean Difference (IV, Random, 95% CI)0.03 [-0.66, 0.73]
4 VAS pain2268Mean Difference (IV, Random, 95% CI)1.50 [-1.84, 4.84]
5 Knee pain (KSS pain)3750Mean Difference (IV, Random, 95% CI)0.60 [-0.39, 1.60]
6 WOMAC total3395Mean Difference (IV, Random, 95% CI)1.59 [-1.32, 4.50]
7 Knee Society Clinical score81110Mean Difference (IV, Random, 95% CI)0.16 [-1.11, 1.43]
8 Knee Society Functional score61012Mean Difference (IV, Random, 95% CI)-1.42 [-4.66, 1.82]
9 Hospital Special Surgery score3635Mean Difference (IV, Random, 95% CI)-0.55 [-2.11, 1.01]
10 Knee Society total score2193Mean Difference (IV, Random, 95% CI)-0.38 [-11.23, 10.47]
11 SF-12 mental2300Mean Difference (IV, Random, 95% CI)0.39 [-5.10, 5.87]
12 Radiological: Radiolucent lines4500Odds Ratio (M-H, Random, 95% CI)0.80 [0.47, 1.35]
13 Radiological: Femorotibial angle4693Mean Difference (IV, Random, 95% CI)0.09 [-0.29, 0.47]
14 Radiological: Rollback2110Mean Difference (IV, Random, 95% CI)2.78 [-9.57, 15.13]
15 Radiological: Tibial slope298Mean Difference (IV, Random, 95% CI)-0.37 [-1.21, 0.48]
Analysis 3.1.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 1 Range of motion.

Analysis 3.2.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 2 Flexion angle.

Analysis 3.3.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 3 Extension angle.

Analysis 3.4.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 4 VAS pain.

Analysis 3.5.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 5 Knee pain (KSS pain).

Analysis 3.6.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 6 WOMAC total.

Analysis 3.7.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 7 Knee Society Clinical score.

Analysis 3.8.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 8 Knee Society Functional score.

Analysis 3.9.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 9 Hospital Special Surgery score.

Analysis 3.10.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 10 Knee Society total score.

Analysis 3.11.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 11 SF-12 mental.

Analysis 3.12.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 12 Radiological: Radiolucent lines.

Analysis 3.13.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 13 Radiological: Femorotibial angle.

Analysis 3.14.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 14 Radiological: Rollback.

Analysis 3.15.

Comparison 3 Posterior cruciate ligament retention versus posterior stabilised sacrifice, Outcome 15 Radiological: Tibial slope.

Appendices

Appendix 1. Search strategy (syntax) for all databases

PubMed

1. "Arthroplasty, Replacement, Knee"[Mesh]
2. "Knee Prosthesis"[Mesh]
3. "knee replacement arthroplasty"[tw]
4. "total knee arthroplasty"[tw]
5. "total knee"[tw]
6. tka[tw]
7. "total knee replacement"[tw]
8. "knee prosthesis"[tw]
9. "knee implantation"[tw]
10. "knee implant"[tw]
11. "knee implants"[tw]
12. "knee prosthesis"[tw]
13. "knee joint replacement"[tw]
14. "knee joint arthroplasty"[tw]
15. tkr[tw]
16. "Knee Replacement Arthroplasties"[tw]
17. "Total Knee Replacements"[tw]
18. "Knee Prostheses"[tw]
19. "Knee endoprosthesis"[tw]
20. "Knee endoprostheses"[tw]
21. "Knee joint arthroplasty"[tw]
22. "Knee joint arthroplasties"[tw]
23. "knee joint prosthesis"[tw]
24. "knee joint prostheses"[tw]
25. "knee prosthetic"[tw]
26. "Knee endoprosthetic"[tw]
27. "knee joint prosthetic"[tw]
28. "Knee joint endoprosthetic"[tw]
29. "knee prosthetics"[tw]
30. "Knee endoprosthetics"[tw]
31. "knee joint prosthetics"[tw]
32. "Knee joint endoprosthetics"[tw]
33. "Knee replacement"[tw]
34. "Knee replacements"[tw]
35. "knee arthroplasty"[tw]
36. "knee arthroplasties"[tw]
37. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34 or 35 or 36
38. "osteoarthritis"[Mesh]
39. "arthritis"[Mesh]
40. "posterior cruciate ligament"[Mesh]
41. Osteoarthrosis[tw]
42. Osteoarthroses[tw]
43. Osteoarthritides[tw]
44. Osteoarthritis[tw]
45. Osteoartrosis[tw]
46. Osteoartroses[tw]
47. Osteoartritides[tw]
48. Osteoartritis[tw]
49. Degenerative Arthritis[tw]
50. Degenerative Arthritides[tw]
51. Degenerative Artritis[tw]
52. Degenerative Artritides[tw]
53. Arthrosis[tw]
54. Arthroses[tw]
55. Arthritides[tw]
56. Arthritis[tw]
57. arthritic[tw]
58. RA[tw]
59. rheumatoid[tw]
60. rheumatic[tw]
61. Artrosis[tw]
62. Artroses[tw]
63. Artritides[tw]
64. Artritis[tw]
65. Osteoarthrosis Deformans[tw]
66. Osteoartrosis Deformans[tw]
67. Posterior Cruciate Ligament[tw]
68. Posterior Cruciate Ligaments[tw]
69. Cruciate[tw]
70. PCL[tw]
71. 38 or 29 or 40 or 41 or 42 or 43 or 44 or 45 or 46 or 47 or 48 or 49 or 50 or 51 or 52 or 53 or 54 or 55 or 56 or 57 or 58 or 59 or 60 or 61 or 62 or 63 or 64 or 65 or 66 or 67 or 68 or 69 or 70
72. "randomized controlled trial"[Publication Type]
73. randomized controlled trials as topic"[Mesh]
74. "random allocation"[Mesh]
75. "double-blind method"[Mesh]
76. "single-blind method"[Mesh]
77. "placebos"[Mesh]
78. random*[tw]
79. ramdom*[tw]
80. ramdon*[tw]
81. randon*[tw]
82. rct[tw]
83. rct's[tw]
84. rcts[tw]
85. placebo*[tw]
86. random*[tw]
87. compare*[ti]
88. versus[ti]
89. vs[ti]
90. single[tw]
91. double[tw]
92. treble[tw]
93. triple[tw]
94. mask*[tw]
95. blind*[tw]
96. 90 or 91 or 92 or 93
97. 94 or 95
98. 96 and 97
99. 72 or 73 or 74 or 75 or 76 or 77 or 78 or 79 or 80 or 81 or 82 or 83 or 84 or 85 or 86 or 87 or 88 or 89 or 98
100. 37 and  71 and 99

EMBASE

1. exp knee arthroplasty/
2. "knee replacement arthroplasty"
3. "total knee arthroplasty".mp
4. "total knee".mp
5. tka.mp
6. "total knee replacement".mp
7. "knee prosthesis".mp
8. "knee implantation".mp
9. "knee implant".mp
10. "knee implants".mp
11. "knee prosthesis".mp
12. "knee joint replacement".mp
13. "knee joint arthroplasty".mp
14. tkr.mp
15. "Knee Replacement Arthroplasties".mp
16. "Total Knee Replacements".mp
17. "Knee Prostheses".mp
18. "Knee endoprosthesis".mp
19. "Knee endoprostheses".mp
20. "Knee joint arthroplasty".mp
21. "Knee joint arthroplasties".mp
22. "knee joint prosthesis".mp
23. "knee joint prostheses".mp
24. "knee prosthetic".mp
25. "Knee endoprosthetic".mp
26. "knee joint prosthetic".mp
27. "Knee joint endoprosthetic".mp
28. "knee prosthetics".mp
29. "Knee endoprosthetics".mp
30. "knee joint prosthetics".mp
31. "Knee joint endoprosthetics".mp
32. "Knee replacement".mp
33. "Knee replacements".mp
34. "knee arthroplasty".mp
35. "knee arthroplasties".mp
37. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34 or 35 or 36
38. exp osteoarthritis/
39. exp Arthritis/
40. exp knee ligament/
41. Osteoarthrosis.mp
42. Osteoarthroses.mp
43. Osteoarthritides.mp
44. Osteoarthritis.mp
45. Osteoartrosis.mp
46. Osteoartroses.mp
47. Osteoartritides.mp
48. Osteoartritis.mp
49. Degenerative Arthritis.mp
50. Degenerative Arthritides.mp
51. Degenerative Artritis.mp
52. Degenerative Artritides.mp
53. Arthrosis.mp
54. Arthroses.mp
55. Arthritides.mp
56. Arthritis.mp
57. arthritic.mp
58. RA.mp
59. rheumatoid.mp
60. rheumatic.mp
61. Artrosis.mp
62. Artroses.mp
63. Artritides.mp
64. Artritis.mp
65. Osteoarthrosis Deformans.mp
66. Osteoartrosis Deformans.mp
67. Posterior Cruciate Ligament.mp
68. Posterior Cruciate Ligaments.mp
69. Cruciate.mp
70. PCL.mp
71. 38 or 29 or 40 or 41 or 42 or 43 or 44 or 45 or 46 or 47 or 48 or 49 or 50 or 51 or 52 or 53 or 54 or 55 or 56 or 57 or 58 or 59 or 60 or 61 or 62 or 63 or 64 or 65 or 66 or 67 or 68 or 69 or 70
72. randomized controlled trial/
73. randomization/
74. triple blind procedure/
75. double blind procedure/
76. single blind procedure/
77. placebo/
78. "random allocation".mp
79. "double-blind*".mp
80. "single-blind*".mp
81. placebo.mp
82. placebos.mp
83. random*.mp
84. ramdom*.mp
85. ramdon*.mp
86. randon*.mp
87. rct.mp
88. rct's.mp
89.rcts
90. single.mp
91. double.mp
92. treble.mp
93. triple.mp
94. 90 or 91 or 92 or 93
95. mask*.mp
96. blind*.mp
97. 95 or 96
98. 94 and 97
99. placebo*.mp
100. random*.mp
101 compare*.ti
102 versus.ti
103. vs.ti
104. 72 or 73 or 74 or 75 or 76 or 77 or 78 or 79 or 80 or 81 or 82 or 83 or 84 or 85 or 86 or 87 or 88 or 89 or 98 or 99 or 100 or 101 or 102 or 103
105. 37 and  71 and 104

Web of Science

1. TS="knee arthroplasty"
2. TS="knee replacement arthroplasty"
3. TS="total knee arthroplasty"
4. TS="total knee"
5. TS=tka
6. TS="total knee replacement"
7. TS="knee prosthesis"
8. TS="knee implantation"
9. TS="knee implant"
10. TS="knee implants"
11. TS="knee prosthesis"
12. TS="knee joint replacement"
13. TS="knee joint arthroplasty"
14. TS=tkr
15. TS="Knee Replacement Arthroplasties"
16. TS="Total Knee Replacements"
17. TS="Knee Prostheses"
18. TS="Knee endoprosthesis"
19. TS="Knee endoprostheses"
20. TS="Knee joint arthroplasty"
21. TS="Knee joint arthroplasties"
22. TS="knee joint prosthesis"
23. TS="knee joint prostheses"
24. TS="knee prosthetic"
25. TS="Knee endoprosthetic"
26. TS="knee joint prosthetic"
27. TS="Knee joint endoprosthetic"
28. TS="knee prosthetics"
29. TS="Knee endoprosthetics"
30. TS="knee joint prosthetics"
31. TS="Knee joint endoprosthetics"
32. TS="Knee replacement"
34. TS="Knee replacements"
35. TS="knee arthroplasty"
36. TS="knee arthroplasties"

37. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34 or 35 or 36

38 TS=osteoarthriti*
39. TS=arthriti*
40. TS=Osteoarthrosis
41. TS=Osteoarthroses
42. TS=Osteoarthritides
43. TS=Osteoarthritis
44. TS=Osteoartrosis
45. TS=Osteoartroses
46. TS=Osteoartritides
47. TS=Osteoartritis
48. TS=Degenerative Arthritis
49. TS=Degenerative Arthritides
50. TS=Degenerative Artritis
51. TS=Degenerative Artritides
52. TS=Arthrosis
53. TS=Arthroses
54. TS=Arthritides
55. TS=Arthritis
56. TS=arthritic
57. TS=RA
58. TS=rheumatoid
59. TS=rheumatic
60. TS=Artrosis
61. TS=Artroses
62. TS=Artritides
63. TS=Artritis
64. TS=Osteoarthrosis Deformans
65. TS=Osteoartrosis Deformans
66. TS=Posterior Cruciate Ligament
67. TS=Posterior Cruciate Ligaments
68. TS=Cruciate
69. TS=PCL

70. 38 or 29 or 40 or 41 or 42 or 43 or 44 or 45 or 46 or 47 or 48 or 49 or 50 or 51 or 52 or 53 or 54 or 55 or 56 or 57 or 58 or 59 or 60 or 61 or 62 or 63 or 64 or 65 or 66 or 67 or 68 or 69

71. TS=randomized controlled trial
72. TS=randomization
73. TS=triple blind procedure
74. TS=double blind procedure
75. TS=single blind procedure
76. TS=placebo
77. TS="random allocation"
78. TS="double-blind*"
79. TS="single-blind*"
80. TS=placebo
81. TS=placebos
82. TS=random*
83. TS=ramdom*
84. TS=ramdon*
85. TS=randon*
86. TS=rct
87. TS=rcts
88. TS=single
89. TS=double
90. TS=treble
91. TS=triple
92. 88 or 89 or 90 or 91

93. TS=mask*
94. TS=blind*

95. 93 or 94

96. 92 and 95
97. TS=placebo*
98. TS=random*
99. TI=compare*
100. TI=versus
101. TI=vs

102. 71 or 72 or 73 or 74 or 75 or 76 or 77 or 78 or 79 or 80 or 81 or 82 or 83 or 84 or 85 or 86 or 87 or 96 or 97 or 98 or 99 or 100 or 101

103. 37 and 70 and 102

Current Contents Connect

1. TS="knee arthroplasty"
2. TS="knee replacement arthroplasty"
3. TS="total knee arthroplasty"
4. TS="total knee"
5. TS=tka
6. TS="total knee replacement"
7. TS="knee prosthesis"
8. TS="knee implantation"
9. TS="knee implant"
10. TS="knee implants"
11. TS="knee prosthesis"
12. TS="knee joint replacement"
13. TS="knee joint arthroplasty"
14. TS=tkr
15. TS="Knee Replacement Arthroplasties"
16. TS="Total Knee Replacements"
17. TS="Knee Prostheses"
18. TS="Knee endoprosthesis"
19. TS="Knee endoprostheses"
20. TS="Knee joint arthroplasty"
21. TS="Knee joint arthroplasties"
22. TS="knee joint prosthesis"
23. TS="knee joint prostheses"
24. TS="knee prosthetic"
25. TS="Knee endoprosthetic"
26. TS="knee joint prosthetic"
27. TS="Knee joint endoprosthetic"
28. TS="knee prosthetics"
29. TS="Knee endoprosthetics"
30. TS="knee joint prosthetics"
31. TS="Knee joint endoprosthetics"
32. TS="Knee replacement"
34. TS="Knee replacements"
35. TS="knee arthroplasty"
36. TS="knee arthroplasties"

37. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34 or 35 or 36

38 TS=osteoarthriti*
39. TS=arthriti*
40. TS=Osteoarthrosis
41. TS=Osteoarthroses
42. TS=Osteoarthritides
43. TS=Osteoarthritis
44. TS=Osteoartrosis
45. TS=Osteoartroses
46. TS=Osteoartritides
47. TS=Osteoartritis
48. TS=Degenerative Arthritis
49. TS=Degenerative Arthritides
50. TS=Degenerative Artritis
51. TS=Degenerative Artritides
52. TS=Arthrosis
53. TS=Arthroses
54. TS=Arthritides
55. TS=Arthritis
56. TS=arthritic
57. TS=RA
58. TS=rheumatoid
59. TS=rheumatic
60. TS=Artrosis
61. TS=Artroses
62. TS=Artritides
63. TS=Artritis
64. TS=Osteoarthrosis Deformans
65. TS=Osteoartrosis Deformans
66. TS=Posterior Cruciate Ligament
67. TS=Posterior Cruciate Ligaments
68. TS=Cruciate
69. TS=PCL

70. 38 or 29 or 40 or 41 or 42 or 43 or 44 or 45 or 46 or 47 or 48 or 49 or 50 or 51 or 52 or 53 or 54 or 55 or 56 or 57 or 58 or 59 or 60 or 61 or 62 or 63 or 64 or 65 or 66 or 67 or 68 or 69

71. TS=randomized controlled trial
72. TS=randomization
73. TS=triple blind procedure
74. TS=double blind procedure
75. TS=single blind procedure
76. TS=placebo
77. TS="random allocation"
78. TS="double-blind*"
79. TS="single-blind*"
80. TS=placebo
81. TS=placebos
82. TS=random*
83. TS=ramdom*
84. TS=ramdon*
85. TS=randon*
86. TS=rct
87. TS=rcts
88. TS=single
89. TS=double
90. TS=treble
91. TS=triple
92. 88 or 89 or 90 or 91

93. TS=mask*
94. TS=blind*

95. 93 or 94

96. 92 and 95
97. TS=placebo*
98. TS=random*
99. TI=compare*
100. TI=versus
101. TI=vs

102. 71 or 72 or 73 or 74 or 75 or 76 or 77 or 78 or 79 or 80 or 81 or 82 or 83 or 84 or 85 or 86 or 87 or 96 or 97 or 98 or 99 or 100 or 101

103. 37 and 70 and 102

Cochrane CENTRAL

1. "knee replacement arthroplasty"
2. "total knee arthroplasty"
3. "total knee"
4. tka
5. "total knee replacement"
6. "knee prosthesis"
7. "knee implantation"
8. "knee implant"
9. "knee implants"
10. "knee prosthesis"
11. "knee joint replacement"
12. "knee joint arthroplasty"
13. tkr
14. "Knee Replacement Arthroplasties"
15. "Total Knee Replacements"
16. "Knee Prostheses"
17. "Knee endoprosthesis"
18. "Knee endoprostheses"
19. "Knee joint arthroplasty"
20. "Knee joint arthroplasties"
21. "knee joint prosthesis"
22. "knee joint prostheses"
23. "knee prosthetic"
24. "Knee endoprosthetic"
25. "knee joint prosthetic"
26. "Knee joint endoprosthetic"
27. "knee prosthetics"
28. "Knee endoprosthetics"
29. "knee joint prosthetics"
30. "Knee joint endoprosthetics"
31. "Knee replacement"
32. "Knee replacements"
33. "knee arthroplasty"
34. "knee arthroplasties"

35. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34

36. Osteoarthrosis
37. Osteoarthroses
38. Osteoarthritides
39. Osteoarthritis
40. Osteoartrosis
41. Osteoartroses
42. Osteoartritides
43. Osteoartritis
44. Degenerative Arthritis
45. Degenerative Arthritides
46. Degenerative Artritis
47. Degenerative Artritides
48. Arthrosis
49. Arthroses
50. Arthritides
51. Arthritis
52. arthritic
53. RA
54. rheumatoid rheumatic
55. Artrosis
56. Artroses
57. Artritides
58. Artritis
59. Osteoarthrosis
60. Deformans
61. Osteoartrosis Deformans
62. Posterior Cruciate Ligament
63. Posterior Cruciate Ligaments
64. Cruciate
65. PCL

66. 36 or 37 or 38 or 29 or 40 or 41 or 42 or 43 or 44 or 45 or 46 or 47 or 48 or 49 or 50 or 51 or 52 or 53 or 54 or 55 or 56 or 57 or 58 or 59 or 60 or 61 or 62 or 63 or 64 or 65

67. 35 and 66

CINAHL

1. "knee replacement arthroplasty"
2. "total knee arthroplasty"
3. "total knee"
4. tka
5. "total knee replacement"
6. "knee prosthesis"
7. "knee implantation"
8. "knee implant"
9. "knee implants"
10. "knee prosthesis"
11. "knee joint replacement"
12. "knee joint arthroplasty"
13. tkr
14. "Knee Replacement Arthroplasties"
15. "Total Knee Replacements"
16. "Knee Prostheses"
17. "Knee endoprosthesis"
18. "Knee endoprostheses"
19. "Knee joint arthroplasty"
20. "Knee joint arthroplasties"
21. "knee joint prosthesis"
22. "knee joint prostheses"
23. "knee prosthetic"
24. "Knee endoprosthetic"
25. "knee joint prosthetic"
26. "Knee joint endoprosthetic"
27. "knee prosthetics"
28. "Knee endoprosthetics"
29. "knee joint prosthetics"
30. "Knee joint endoprosthetics"
31. "Knee replacement"
32. "Knee replacements"
33. "knee arthroplasty"
34. "knee arthroplasties"
35. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34
36. Osteoarthrosis
37. Osteoarthroses
38. Osteoarthritides
39. Osteoarthritis
40. Osteoartrosis
41. Osteoartroses
42. Osteoartritides
43. Osteoartritis
44. Degenerative Arthritis
45. Degenerative Arthritides
46. Degenerative Artritis
47. Degenerative Artritides
48. Arthrosis
49. Arthroses
50. Arthritides
51. Arthritis
52. arthritic
53. RA
54. rheumatoid rheumatic
55. Artrosis
56. Artroses
57. Artritides
58. Artritis
59. Osteoarthrosis
60. Deformans
61. Osteoartrosis Deformans
62. Posterior Cruciate Ligament
63. Posterior Cruciate Ligaments
64. Cruciate
65. PCL
66. 36 or 37 or 38 or 29 or 40 or 41 or 42 or 43 or 44 or 45 or 46 or 47 or 48 or 49 or 50 or 51 or 52 or 53 or 54 or 55 or 56 or 57 or 58 or 59 or 60 or 61 or 62 or 63 or 64 or 65
67. randomized controlled trial
68. randomization
69. triple blind procedure
70. double blind procedure
71. single blind procedure
72. placebo
73. "random allocation"
74. "double-blind*"
75. "single-blind*"
76. placebo
77. placebos
78. random*
79. ramdom*
80. ramdon*
81. randon*
82. rct
83. rcts
84. single
85. double
86. treble
87. triple
88. 84 or 85 or 86 or 87
89. mask*
90. blind*
91. 89 or 90
92. 88 and 91
93. placebo*
94. random*
95. 67 or 68 or 69 or 70 or 71 or 72 or 73 or 74 or 75 or 76 or 77 or 78 or 79 or 80 or 81 or 82 or 83 or 92 or 93 or 94
96. 35 and 66 and 95

Academic Search Premier

1. "knee replacement arthroplasty" in TI/AB/KW/SU
2. "total knee arthroplasty" in TI/AB/KW/SU
3. "total knee" in TI/AB/KW/SU
4. tka in TI/AB/KW/SU
5. "total knee replacement" in TI/AB/KW/SU
6. "knee prosthesis" in TI/AB/KW/SU
7. "knee implantation" in TI/AB/KW/SU
8. "knee implant" in TI/AB/KW/SU
9. "knee implants" in TI/AB/KW/SU
10. "knee prosthesis" in TI/AB/KW/SU
11. "knee joint replacement" in TI/AB/KW/SU
12. "knee joint arthroplasty" in TI/AB/KW/SU
13. tkr in TI/AB/KW/SU
14. "Knee Replacement Arthroplasties" in TI/AB/KW/SU
15. "Total Knee Replacements" in TI/AB/KW/SU
16. "Knee Prostheses" in TI/AB/KW/SU
17. "Knee endoprosthesis" in TI/AB/KW/SU
18. "Knee endoprostheses" in TI/AB/KW/SU
19. "Knee joint arthroplasty" in TI/AB/KW/SU
20. "Knee joint arthroplasties" in TI/AB/KW/SU
21. "knee joint prosthesis" in TI/AB/KW/SU
22. "knee joint prostheses" in TI/AB/KW/SU
23. "knee prosthetic" in TI/AB/KW/SU
24. "Knee endoprosthetic" in TI/AB/KW/SU
25. "knee joint prosthetic" in TI/AB/KW/SU
26. "Knee joint endoprosthetic" in TI/AB/KW/SU
27. "knee prosthetics" in TI/AB/KW/SU
28. "Knee endoprosthetics" in TI/AB/KW/SU
29. "knee joint prosthetics" in TI/AB/KW/SU
30. "Knee joint endoprosthetics" in TI/AB/KW/SU
31. "Knee replacement" in TI/AB/KW/SU
32. "Knee replacements" in TI/AB/KW/SU
33. "knee arthroplasty" in TI/AB/KW/SU
34. "knee arthroplasties" in TI/AB/KW/SU
35. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28 or 29 or 30 or 31 or 32 or 33 or 34
36. Osteoarthrosis in TI/AB/KW/SU
37. Osteoarthroses in TI/AB/KW/SU
38. Osteoarthritides in TI/AB/KW/SU
39. Osteoarthritis in TI/AB/KW/SU
40. Osteoartrosis in TI/AB/KW/SU
41. Osteoartroses in TI/AB/KW/SU
42. Osteoartritides in TI/AB/KW/SU
43. Osteoartritis in TI/AB/KW/SU
44. Degenerative Arthritis in TI/AB/KW/SU
45. Degenerative Arthritides in TI/AB/KW/SU
46. Degenerative Artritis in TI/AB/KW/SU
47. Degenerative Artritides in TI/AB/KW/SU
48. Arthrosis in TI/AB/KW/SU
49. Arthroses in TI/AB/KW/SU
50. Arthritides in TI/AB/KW/SU
51. Arthritis in TI/AB/KW/SU
52. arthritic in TI/AB/KW/SU
53. RA in TI/AB/KW/SU
54. rheumatoid rheumatic in TI/AB/KW/SU
55. Artrosis in TI/AB/KW/SU
56. Artroses in TI/AB/KW/SU
57. Artritides in TI/AB/KW/SU
58. Artritis in TI/AB/KW/SU
59. Osteoarthrosis in TI/AB/KW/SU
60. Deformans in TI/AB/KW/SU
61. Osteoartrosis Deformans in TI/AB/KW/SU
62. Posterior Cruciate Ligament in TI/AB/KW/SU
63. Posterior Cruciate Ligaments in TI/AB/KW/SU
64. Cruciate in TI/AB/KW/SU
65. PCL in TI/AB/KW/SU
66. 36 or 37 or 38 or 29 or 40 or 41 or 42 or 43 or 44 or 45 or 46 or 47 or 48 or 49 or 50 or 51 or 52 or 53 or 54 or 55 or 56 or 57 or 58 or 59 or 60 or 61 or 62 or 63 or 64 or 65
67. randomized controlled trial in TI/AB/KW/SU
68. randomization in TI/AB/KW/SU
69. triple blind procedure in TI/AB/KW/SU
70. double blind procedure in TI/AB/KW/SU
71. single blind procedure in TI/AB/KW/SU
72. placebo in TI/AB/KW/SU
73. "random allocation" in TI/AB/KW/SU
74. "double-blind*" in TI/AB/KW/SU
75. "single-blind*" in TI/AB/KW/SU
76. placebo in TI/AB/KW/SU
77. placebos in TI/AB/KW/SU
78. random* in TI/AB/KW/SU
79. ramdom* in TI/AB/KW/SU
80. ramdon* in TI/AB/KW/SU
81. randon* in TI/AB/KW/SU
82. rct in TI/AB/KW/SU
83. rcts in TI/AB/KW/SU
84. single in TI/AB/KW/SU
85. double in TI/AB/KW/SU
86. treble in TI/AB/KW/SU
87. triple in TI/AB/KW/SU
88. 84 or 85 or 86 or 87
89. mask* in TI/AB/KW/SU
90. blind* in TI/AB/KW/SU
91. 89 or 90
92. 88 and 91
93. placebo* in TI/AB/KW/SU
94. random* in TI/AB/KW/SU
95. 67 or 68 or 69 or 70 or 71 or 72 or 73 or 74 or 75 or 76 or 77 or 78 or 79 or 80 or 81 or 82 or 83 or 92 or 93 or 94
96. 35 and 66 and 95

ScienceDirect

1. TITLE-ABSTR-KEY("knee replacement")
2. TITLE-ABSTR-KEY("total knee")

3. TITLE-ABSTR-KEY(tka)
4. TITLE-ABSTR-KEY("knee prosthesis")
5. TITLE-ABSTR-KEY("knee implantation")
6. TITLE-ABSTR-KEY("knee implant")
7. TITLE-ABSTR-KEY("knee implants")
8. TITLE-ABSTR-KEY("knee joint replacement")
9. TITLE-ABSTR-KEY("knee joint arthroplasty")
10. TITLE-ABSTR-KEY(tkr)
11. TITLE-ABSTR-KEY("Knee Prostheses")
12. TITLE-ABSTR-KEY("Knee endoprosthesis")
13. TITLE-ABSTR-KEY("Knee endoprostheses")
14. TITLE-ABSTR-KEY("Knee joint arthroplasty")
15. TITLE-ABSTR-KEY("Knee joint arthroplasties")
16. TITLE-ABSTR-KEY("knee joint prosthesis")
17. TITLE-ABSTR-KEY("knee joint prostheses")
18. TITLE-ABSTR-KEY("knee prosthetic")
19. TITLE-ABSTR-KEY("Knee endoprosthetic")
20. TITLE-ABSTR-KEY("knee joint prosthetic")
21. TITLE-ABSTR-KEY("Knee joint endoprosthetic")
22. TITLE-ABSTR-KEY("knee prosthetics")
23. TITLE-ABSTR-KEY("Knee endoprosthetics")
24. TITLE-ABSTR-KEY("knee joint prosthetics")
25. TITLE-ABSTR-KEY("Knee joint endoprosthetics")
26. TITLE-ABSTR-KEY("Knee replacements")
27. TITLE-ABSTR-KEY("knee arthroplasty")
28. TITLE-ABSTR-KEY("knee arthroplasties")
29. 1 or 2 or 3 or 4 or 5 or 6 or 7 or 8 or 9 or 10 or 11 or 12 or 13 or 14 or 15 or 16 or 17 or 18 or 19 or 20 or 21 or 22 or 23 or 24 or 25 or 26 or 27 or 28
30. TITLE-ABSTR-KEY(Osteoarthritis)
31. TITLE-ABSTR-KEY(Arthritis)
32. TITLE-ABSTR-KEY(Posterior Cruciate Ligament)
33. TITLE-ABSTR-KEY(Posterior Cruciate Ligaments)
34. TITLE-ABSTR-KEY(Cruciate)
35. TITLE-ABSTR-KEY(PCL)
36. 30 or 31 or 32 or 33 or 34 or 35
37. TITLE-ABSTR-KEY(randomized)
38. TITLE-ABSTR-KEY(randomization)
39. TITLE-ABSTR-KEY(random*)
40. TITLE-ABSTR-KEY(ramdom*)
41. TITLE-ABSTR-KEY(ramdon*)
42. TITLE-ABSTR-KEY(randon*)
43. TITLE-ABSTR-KEY(rct)

44. 37 or 38 or 39 or 40 or 41 or 42 or 43

45. 29 and 36 and 44

What's new

DateEventDescription
7 December 2012New search has been performedNew search with 10 new studies.
6 December 2012New citation required but conclusions have not changedNew authorship.

History

DateEventDescription
13 June 2008AmendedConverted to new review format. CMSG ID C071-R

Contributions of authors

Original review

W Jacobs and D Clement: writing the protocol, selecting the studies, extracting data, and writing the manuscript

A Wymenga: clinical interpretation of the results

Update review

W Verra, L vd Boom and W Jacobs: updating the protocol, selecting studies, extracting data, writing manuscript

R Nelissen: writing manuscript, interpretation of results

A Wymenga, D Clement: correcting the manuscript

Declarations of interest

None known

Differences between protocol and review

Compared to the protocol, some deviations occurred during the process of developing the review.
First, the decision was made, as requested by the reviewer and editor, to included quasi-randomised trials.
Furthermore, in accordance with the reviewers and editor, the definitions of the major and minor outcomes changed slightly.
The seven major outcomes now are, 1. performance based: range of motion, 2. patients' experience: knee pain, 3. implant survival rate, 4. validated questionnaires on quality of life or function (that is WOMAC), 5. patient satisfaction, 6. complication rate, 7. re-operations other than revision surgery.
The 'rheumatoid arthritis' is removed from the title because we felt it did not add anything to the rest of the title.

Characteristics of studies

Characteristics of included studies [ordered by study ID]

Aglietti 2005

MethodsRandomised controlled trial. Method of randomisation: quasi-randomisation by odd/even numbers
Participants

Group A: 103 knees (98 patients)

Group B: 107 knees (99 patients)

Inclusion: Not described (all osteoarthritic patients between Jan 1999 and Dec 2000)
Exclusion: Not described

Age: Group A 71 years, Group B 69.5 years

Gender: Group A 86% female, Group B 81% female

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection + posterior stabilised
Brand: LPS/MBK, Zimmer, Warsaw, Ind, USA
Patella: resurfaced in all cases
Bearing: Group A mobile bearing (MBK), Group B fixed bearing (LPS)
Cement: Yes
Outcomes

VAS pain

Patellar scoring system

Knee Society roentgenographic evaluation system

Radiolucencies

Mechanical axis

Knee Society score (functional and clinical)

ROM

Notes

Mean duration of follow-up: 36 months (30-48)

Funding source: not described

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskQuasi-randomisation based on odd/even patient numbers
Allocation concealment (selection bias)High riskQuasi-randomisation based on odd/even patient numbers
Blinding (performance bias and detection bias)
All outcomes
Unclear riskDue to the randomisation method blinding of treatment arm is not possible
Blinding of participants and personnel (performance bias)
All outcomes
Low riskAuthors state that evaluation during follow-up visit was blinded for type of arthroplasty
Blinding of outcome assessment (detection bias)
All outcomes
Low riskAuthors state that evaluation during follow-up visit was blinded for type of arthroplasty
Incomplete outcome data (attrition bias)
All outcomes
Low risk3 patients lost to follow-up at the final follow-up moment
Selective reporting (reporting bias)Low riskAll outcome measures seem reported

Catani 2004

MethodsRandomised controlled trial. Method of randomisation, allocation concealment or blinding not described
Participants

Group A: 20 knees/patients
Group B: 20 knees/patients
Inclusion: Not described (osteoarthritis selected)
Exclusion: Not described

Age: Group A 70 ± 6.0 (60 to 82), Group B 71 ± 7.0 (48 to 80)

Gender: (M:F) Group A 7:13 (65% female), Group B 5:15 (75% female)

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection + posterior stabilised
Brand: Optetrak, Exactech, Gainesville, Fl, US
Patella: Not described
Bearing: Not described
Cement: Yes
OutcomesRadiological: RSA
Knee Society Score
Hospital Special Surgery Score
Range of motion
Notes

Duration of follow-up: 2 years
Follow-up rate: 100%

Funding source: no external funding

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot described
Allocation concealment (selection bias)Unclear riskNot described
Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot described
Blinding of participants and personnel (performance bias)
All outcomes
High riskFor radiological outcomes (e.g. RSA), personnel (e.g. physicians) can see on the images what arthroplasty design was implanted
Blinding of outcome assessment (detection bias)
All outcomes
High riskFor radiological outcomes (e.g. RSA), personnel (e.g. physicians) can see on the images what arthroplasty design was implanted
Incomplete outcome data (attrition bias)
All outcomes
Low riskFollow-up rate 100%
Selective reporting (reporting bias)Low riskAll outcome measurements are reported

Chaudhary 2008

MethodsRandomised controlled trial. Method of randomisation: computer generated block randomisation; concealment of allocation: opaque envelopes; blinding: patients are blinded, physiotherapists measuring primary outcome were blinded
Participants

Group A: 51 knees/patients

Group B: 49 knees/patients

Inclusion:

Osteoarthritis (primary total knee arthroplasty)

Intact posterior cruciate ligament at surgery

Exclusion:

Inflammatory arthritis

Bonegrafting required

Varus/valgus deformity >15 degrees

Previous high tibial osteotomy

Unable to understand study requirements

Age: Group A 69.2 ± 9.1, Group B 70.2 ± 8.4

Gender: Group A 53% female, Group B 45% female

Interventions

Posterior cruciate ligament:

Group A: Retention

Group B: Resection + posterior stabilised

Brand: SCORPIO total knee system, Stryker Orthopaedics, Mahwah, New Jersey, US

Patella: Free to surgeon's indication

Bearing: Not described

Cement: Free to surgeon's indication

Outcomes

ROM (flexion and extension)

RAND-36

WOMAC total

Notes

Duration of follow-up: 2 years. Follow-up rate: lost to follow-up n = 22 (22%)

Funding source: industry funding is reported

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskBlock randomisation performed by computer
Allocation concealment (selection bias)Low riskOpaque envelopes
Blinding (performance bias and detection bias)
All outcomes
Low riskBlinding was performed
Blinding of participants and personnel (performance bias)
All outcomes
Low riskParticipants and physiotherapists measuring primary outcome were blinded for the randomisation outcome
Blinding of outcome assessment (detection bias)
All outcomes
Low riskPhysiotherapists measuring primary outcome were blinded for the randomisation outcome, radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk22% lost to follow-up
Selective reporting (reporting bias)Low riskAll outcome measures seem reported

Clark 2001

MethodsRandomised controlled trial. Multicentre, stratified by surgeon, method of randomisation, allocation concealment or blinding not described
Participants

Group A: 59 knees/patients
Group B: 69 knees/patients
Inclusion:
Speaking English
57 to 89 years of age
Osteoarthritis, osteoarthritis plus psoriasis, or fracture osteoarthritis
Intact posterior cruciate ligament
Exclusion:
Previous total knee arthroplasty
Patellectomy
High tibial osteotomy
Cruciate ligament reconstruction
Knee sepsis
Flexion <90 degrees
Flexion contracture >15 degrees
Willing to comply with the assessments
Varus >20 and Valgus >15 degrees

Age: Group A: 71.8 ±12.2, Group B 71.2 ±13.6

Gender: Not described

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection + posterior stabilised
Brand: AMK, DePuy / Johnson & Johnson, Warsaw Indiana, US
Patella: Yes
Bearing: Not described
Cement: Yes
OutcomesKnee Society Score
Range of motion
SF-12
WOMAC total
Notes

Duration of follow-up: 6 weeks, 3 and 6 months and yearly thereafter
Follow-up rate: 90% 1 year, 76% 2 years, 51% 3 years

Post-traumatic OA N = 4 (is exclusion criterion for analysis in the review)

Funding source: not described

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot described
Allocation concealment (selection bias)Unclear riskNot described
Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot described
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskNot described
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot described, radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
High riskLosses to follow-up augment with large steps each following year
Selective reporting (reporting bias)Unclear riskOnly the total Knee Society Score was reported. It is more usual to report the clinical and functional score separately giving more insight in the nature of the possible differences between groups

de Andrade 2009

MethodsRandomised controlled trial. Method of randomisation and concealment of allocation not described. Blinding: evaluators were blinded for treatment allocation, surgeon was blind for clinical parameters. Statistician did not have contact with patients and/or surgical team
Participants

Group A: 36 knees/patients

Group B: 49 knees/patients

Inclusion: Not described

Exclusion: Not described

Age: 66.3 (41 to 78)

Gender: (M:F) 22:63 (74% female)

Interventions

Posterior cruciate ligament:

Group A: Retention

Group B: Resection

Brand: Nexgen, Zimmer, Warsaw, Indiana, US

Patella: Not described

Bearing: Not described

Cement: Not described

OutcomesKSS (overall)
Notes

Original article in Portuguese, translated and data extracted by translator of Cochrane Musculoskeletal group, Canada

Duration of follow-up: up to 15.8 months (6wk, 3 m, 6 m, final)

Funding source: not described

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot described
Allocation concealment (selection bias)Unclear riskNot described
Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot described
Blinding of participants and personnel (performance bias)
All outcomes
Low riskObservers blinded
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot described, radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Low risk100% follow-up
Selective reporting (reporting bias)Unclear riskOnly the total Knee Society Score was reported. It is more usual to report the clinical and functional score separately giving more insight in the nature of the possible differences between groups

Harato 2008

MethodsRandomised controlled trial. Method of randomisation: centralized, permuted blocks, concealment of allocation: closed envelopes, blinding: unclear
Participants

Group A: 111 knees (99 patients)

Group B: 111 knees (93 patients)

Inclusion:

Degenerative osteoarthritis

Macroscopically intact posterior cruciate ligament at surgery

Exclusion:

Reumatoid arthritis

Osteonecrosis

Previous high tibial osteotomy

Previous patellectomy

Previous cruciate ligament reconstruction

Previous arthroscopic surgery

Age: Group A 68.3 (49 to 89), Group B 66.0 (44 to 83)

Gender: (M:F) Group A 65:34 (34% female), Group B 61:32 (34% female)

Interventions

Posterior cruciate ligament:

Group A: Retention

Group B: Resection + posterior stabilised

Brand: Genesis II, Smith & Nephew, Memphis, Tennessee, US

Patella: Resurfaced

Bearing: Not described

Cement: Yes

Outcomes

Knee Society Score

WOMAC total

SF-12

Radiographic assessment (lucency at follow-up)

Kinematics (in subset of patients published separately Victor et al 2005)

Notes

Duration of follow-up 5.0-7.3 years. Follow-up rate: lost to follow-up group A N=12 (10.8%), group B N=18 (16.2%)

Data of a subset of patients from the study (the Belgian group) is published in another paper as well;

Victor et al 2005 "Kinematics of posterior cruciate ligament retaining and -substituting total knee arthroplasty"

Funding source: not described (not described in Victor et al 2005 as well)

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskCentralized randomisation, using permutated randomisation blocks, randomisation per centre
Allocation concealment (selection bias)Low riskClosed envelopes
Blinding (performance bias and detection bias)
All outcomes
Unclear riskBlinding unclear
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskBlinding unclear
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskBlinding unclear, radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk13.5% lost to follow-up (N = 30), from this 16 participants deceased during follow-up
Selective reporting (reporting bias)Low riskIt seems all outcomes are reported

Kim 2009

Methods

Randomised controlled trial. Method of randomisation: random distribution of envelopes,

concealment of allocation and blinding: sealed envelope, however, all procedures were bilateral, the first knee received the treatment according to the envelope, the other knee the other treatment. Hence, the second allocation was not concealed. Clinical outcome measured by blinded evaluator

Participants

Group A: 250 knees

Group B: 250 knees

Inclusion:

Bilateral osteoarthritis

Exclusion:

Inflammatory arthritis

OA of the hip restricting mobility

Foot or ankle disorder limiting mobility

Dementia

Neurological disorder: e.g. stroke, affecting mobility

Age: 71.6 ± 6.0 (40 to 84)

Gender: (M:F) 10:240 in total study population (96% female)

Interventions

Posterior cruciate ligament:

Group A: Retention

Group B: Resection + posterior stabilised

Brand: Nexgen, Zimmer, Warsaw, Indiana, US (CR-flex versus Legacy PS-flex)

Patella: Yes

Bearing: Fixed

Cement: Yes

Outcomes

Range of motion

Knee Society Score

Hospital Special Surgery Score

WOMAC pain score

Radiological

Notes

Duration of follow-up: 2.3 years (2 to 3 years). Lost to follow-up: N = 6 (2.3%)

All participants received continuous passive motion postoperatively

Funding source: no external funding

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskRandimisation via sealed envelopes, however unclear if these were shuffled
Allocation concealment (selection bias)Low riskSealed envelopes. Note that treatment allocation of the contra-lateral knee was not concealed, however, investigator could not influence the allocation of treatment of the first knee. There were no violations of the randomisation reported
Blinding (performance bias and detection bias)
All outcomes
Unclear riskSince the treatment was bilateral, knowledge on the allocated intervention was available for the contralateral knee directly after first randomisation
Blinding of participants and personnel (performance bias)
All outcomes
Low riskClinical data obtained by researcher unfamiliar with randomisation outcome
Blinding of outcome assessment (detection bias)
All outcomes
Low riskClinical data obtained by researcher unfamiliar with randomisation outcome, however radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Low riskRelatively little lost to follow-up: 2.3%
Selective reporting (reporting bias)Low riskPart of the data was reported in an appendix. It seems all data are reported

Maruyama 2004

MethodsRandomised controlled trial: quasi-randomisation: alternating sequences, bilateral procedures
Participants

Group A: 20 knees (10 patients)

Group B: 20 knees (10 patients)

Inclusion: bilateral procedure within 2 years

Osteoarthritis

Correction of alignment can be achieved with retention of the posterior cruciate ligament
Exclusion: significant fixed deformity

Age: 74.3 years (65-84)

Gender: 12 female, 8 male (60% female)

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection + posterior stabilised
Brand: PFC from DePuy / Johnson & Johnson, Warsaw, Indiana, US
Patella: Not described
Bearing: Not described
Cement: Yes
OutcomesKnee Society score
Extension angle
Flexion angle
Range of motion
Joint line
Notes

Average follow-up: group A: 31.7 months (24-53), Group B: 30.6 (24-38)

Follow-up rate: 100%

Funding source: not described

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskQuasi-randomisation based on alternating sequence
Allocation concealment (selection bias)High riskQuasi-randomisation based on alternating sequence
Blinding (performance bias and detection bias)
All outcomes
High riskDue to the method of randomisation adequate blinding is not possible
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskNot described
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot described
Incomplete outcome data (attrition bias)
All outcomes
Low risk100% follow-up
Selective reporting (reporting bias)Low riskAll data seems reported

Matsumoto 2012

MethodsRandomised controlled trial. Randomisation according to the envelope technique. Opaqueness of envelopes not described
Participants

Group A: 25 knees/patients

Group B: 25 knees/patients

Inclusion: Pain and loss of function due to osteoarthritis
Exclusion: Valgus deformity

Sever bony defect needing augmentation or bone grafting

Revision total knee arthroplasty

Active joint infection

Bilateral procedures

Age: Group A: 73.5 ± 1.3 years, Group B: 74.4 ± 0.9 years

Gender: 100% females in both groups

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection + posterior stabilised
Brand: NexGen CR/LPS flex, Zimmer, Warsaw, Ind, USA
Patella: Yes
Bearing: Not described
Cement: Not described
Outcomes

Range of motion

Knee Society clinical/functional score

Coronal laxity

Notes

Mean follow-up: Group A: 71.9 (61-83) months, Group B: 70.2 (63-87) months

After 5 years lost to follow-up: Group A: 6 patients, Group B: 3 patients

Funding source: not described

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot described how the order of envelopes was generated
Allocation concealment (selection bias)High riskThe envelope technique is known to be prone to errors
Blinding (performance bias and detection bias)
All outcomes
Unclear riskThe envelope technique does not guarantee blindness
Blinding of participants and personnel (performance bias)
All outcomes
Low riskOutcome measurements were performed by blinded observers
Blinding of outcome assessment (detection bias)
All outcomes
Low riskOutcome measurements were performed by blinded observers
Incomplete outcome data (attrition bias)
All outcomes
Unclear riskGroup A had 24% loss to follow-up and Group B 12% after 5 years
Selective reporting (reporting bias)Low riskAll data seem reported

Misra 2003

MethodsRandomised controlled trial. Table generated randomisation sequence, observer blinded. Method of allocation concealment not described
Participants

Group A: 51 knees (50 patients)
Group B: 54 knees (53 patients)
Inclusion:
Not described (osteoarthritis/rheumatoid arthritis selected)
Exclusion:
Not described

Age: Group A 66.8 (55 to 83), Group B 67.2 (59 to 82)

Gender: (M:F) Group A 17:34 (67% female), Group B 22:32 (59% female)

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection
Brand: Press Fit Condylar (PFC), DePuy, Warsaw Indina, US. Both groups same design
Patella: Criteria for resurfacing (resurfaced in 48 knees)
Bearing: Not described
Cement: Yes
OutcomesHospital Special Surgery Score
Range of motion
Satisfaction (score 1 to 10)
Radiological: rollback and loosening
Notes

Duration of follow-up: 57 months
Follow-up rate: 81%

Funding source: no external funding

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskRandom numbers table used
Allocation concealment (selection bias)Unclear riskNot described
Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot clearly described
Blinding of participants and personnel (performance bias)
All outcomes
Low riskClinical measurements performed by blinded personnel
Blinding of outcome assessment (detection bias)
All outcomes
Low riskClinical measurements performed by blinded personnel, however radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Low risk81% follow-up rate, random losses to follow-up, analysed and described in paper
Selective reporting (reporting bias)Low riskIt seems all outcome measures were reported

Roh 2012

MethodsRandomised controlled trial. Permuted block randomisation. Same arthroplasty design was applied in both treatment arms (deep dish), intention-to-treat analysis
Participants

Group A: 42 knees knees/patients

Group B: 44 knees knees/patients

Inclusion: Primary osteoarthritis
Exclusion: Previous surgery to the affected knee

Age: Group A: 69.8 ± 4.7, Group B: 71.0 ± 4.9

Gender: Group A: M:F 2:40 (95% female), Group B: M:F 3:41 (93% female)

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection
Brand: E-motion TKA system, B. Braun Aesculap, Tuttlingen, Germany
Patella: Some (Group A: 8, Group B: 6)
Bearing: Mobile bearing, rotating
Cement: Yes
Outcomes

Range of motion

Flexion angle

Tibiofemoral angle

Knee Society clinical/functional score

Hospital for Special Surgery score

WOMAC total

Notes

Mean follow-up: Group A: 27.3 ± 3.7 months. Group B: 32.2 ± 4.8 months

Group A 3 patients lost (6.7%), Group B 1 patient lost (2.2%)

Funding source: not described

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Low riskUsing permutated blocks
Allocation concealment (selection bias)Unclear riskNot described
Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot described
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskNot described
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot described
Incomplete outcome data (attrition bias)
All outcomes
Low riskFew patients lost to follow-up
Selective reporting (reporting bias)Low riskAll data seem reported

Seon 2011

MethodsRandomised controlled trial. Randomisation and concealment of allocation: sealed envelopes, blinding: clinical data acquired by unblinded evaluators, radiological measurements performed by evaluators unaware of clinical status of participants
Participants

Group A: 48 knees/patients

Group B: 47 knees/patients

Inclusion:

Osteoarthritis

Minimal range of motion >90 degrees or 90 degrees

Excusion:

Previous open surgery with placement of metallic implants

History of revision total knee arthroplasty

Other than osteoarthritis as indication diagnosis

Restricted mobility

Severe pain after contralateral total knee arthroplasty

Age: Group A 68.2 ± 7.0 (54 to 85), Group B 69.1 ± 6.7 (56 to 81)

Gender: (M:F) 9:86 in total study population

Interventions

Posterior cruciate ligament:

Group A: Retention

Group B: Resection + posterior stabilised

Brand: Nexgen, Zimmer, Warsaw Indiana, US

Patella: Not resurfaced

Bearing: Not described

Cement: Yes

Outcomes

Range of motion (incl weight-bearing and non-weight-bearing maximal flexion)

Hospital Special Surgery Score

WOMAC total

Femorotibial angles

Tibiofemoral kinematics: femoral rollback and tibial rotation

Notes

Duration of follow-up: 2 years, loss to follow-up group A N = 3 (5.9%), group B N = 4 (7.8%)

Funding source: no external funding

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskPile of sealed envelopes, unclear if and how they were shuffled
Allocation concealment (selection bias)Low riskSealed envelopes
Blinding (performance bias and detection bias)
All outcomes
High riskBlinding is not performed ("all range of motion and clinical data obtained were evaluated and recorded by two independent evaluators who were part of the surgical team")
Blinding of participants and personnel (performance bias)
All outcomes
High riskBlinding is not performed
Blinding of outcome assessment (detection bias)
All outcomes
High riskBlinding is not performed, radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Low risk6.9% (N=7) participants lost to follow-up: reasonable
Selective reporting (reporting bias)Low riskAll outcome measures seem reported

Shoji 1994

MethodsRandomised controlled trial. Bilateral procedures, method of randomisation, allocation concealment or blinding not described
Participants

Group A: 28 knees/patients
Group B: 28 knees/patients
Inclusion:
Not described (osteoarthritis/rheumatoid arthritis selected)
Exclusion:
Not described

Age: Not described

Gender: Not described

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection
Brand: Total Condylar Modifier, Biomed, Warsaw Indiana, US, both groups similar design
Patella: Not described
Bearing: Not described
Cement: Not described
OutcomesHospital Special Surgery Score
HSS pain subscore
HSS muscle power subscore
Range of motion
Notes

Duration of follow-up: 2.5 to 4.5 years (3.2 years average)
Follow-up rate: 100%

Funding source: not described

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot described
Allocation concealment (selection bias)Unclear riskNot described
Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot described
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskNot described
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot described, radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Low risk100% follow-up rate
Selective reporting (reporting bias)Low riskIt seems all outcome measures are reported

Straw 2003

MethodsRandomised controlled trial. Observer blinded, method of randomisation or allocation concealment not described
Participants

Group A: 66
Group B: 101

Total 188 patients participating
Inclusion:
Not described (osteoarthritis/rheumatoid arthritis selected)
Exclusion:
Not described

Age: Group cruciate-retaining: 72.6, Group PS: 72.6, Group ligament resection: 74.1

Gender: (M:F) Group A: 37:29, Group PS: 32:27, Group B: 20:22

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection: further randomised to posterior stabilised or standard total knee arthroplasty design
Brand: Genesis I, Smith & Nephew, Memphis, Tennessee, US
Patella: Yes
Bearing: Not described
Cement: Not described
OutcomesKnee Society Score
Range of motion
Pain score
Antero-posterior / medio-lateral stability
Notes

Duration of follow-up: 1 to 6.5 years (3.5 years average)
Follow-up rate: 89%

Funding source: no external funding

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot described
Allocation concealment (selection bias)Unclear riskNot described
Blinding (performance bias and detection bias)
All outcomes
Low riskObserver is blinded
Blinding of participants and personnel (performance bias)
All outcomes
Low riskObserver is blinded
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskRadiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Low riskReasonable follow-up rate
Selective reporting (reporting bias)Low riskIt seems all outcome measures are reported

Tanzer 2002

MethodsRandomised controlled trial. Patient and observer blinded, method of randomisation or allocation concealment not described
Participants

Group A: 20 knees
Group B: 20 knees

A total of 37 patients participated in the study
Inclusion:
Not described (osteoarthritis, rheumatoid arthritis, avascular necrosis selected)
Exclusion:
Not described

Age: Group A: 68 (51 to 86), Group B: 66 (52 to 77)

Gender: (M:F) Group A 5:15 (75% female), Group B 4:16 (80% female)

InterventionsPosterior cruciate ligament:
Group A: Retention
Group B: Resection + posterior stabilised
Brand: Retention: Nexgen; Posterior stabilised: Legacy Zimmer, Warsaw Indiana, US
Patella: Partly (Group A n = 18, Group B n = 17)
Bearing: Not described
Cement: Yes
OutcomesKnee Society Score clinical
Knee Society Score functional
Flexion
Notes

Duration of follow-up: (6 weeks, 3 and 6 months, and 1 and) 2 years
Follow-up rate: 100%

Funding source: no external funding

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskNot described
Allocation concealment (selection bias)Unclear riskNot described
Blinding (performance bias and detection bias)
All outcomes
Unclear riskPatient and observer blinded
Blinding of participants and personnel (performance bias)
All outcomes
Low riskPatient and observer blinded
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskPatient and observer blinded, radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Low risk100% follow-up
Selective reporting (reporting bias)Low riskIt seems all outcome measures are reported

Wang 2004

Methods

Randomised controlled trial. Quasi-randomisation; randomisation based on hospital admission

Due to an inventory shortage of cruciate substituting arthroplasties more patient received a cruciate retaining arthroplasty. No intention-to-treat analysis is reported

Participants

Group A: 157 knees (137 patients)

Group B: 110 knees (91 patients)

Inclusion: osteoarthrtitis and rheumatoid arthritis (rheumatoid: Group A: 20 knees, Group B: 3)
Exclusion: Not described

Age: Group A: 54.5 (31-69), Group B: 55 (20-83)

Gender: Group A: M:F 45:183 (80% female), Group B: M:F 27:110 (80% female)

Interventions

Posterior cruciate ligament:
Group A: Retention
Group B: Resection

Brand: PFC, Johnson & Johnson, Ryndum, Mass, USA
Patella: No
Bearing: Not described
Cement: Yes

Outcomes

Knee Society clinical/functional/pain score

Tibiofemoral angle

Flexion/extension angle

Radiolucencies (%)

SF-12 functional score

Ligament laxity

Notes

Lost to follow-up: 42 patients (43 knees) 16% at 2 years follow-up

Average follow-up: 42 ± 18 months (range 24 to 66 months)

Funding source: non-commercial grant from National Science Council reported

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)High riskQuasi-randomisation based on hospital admission
Allocation concealment (selection bias)High riskQuasi-randomisation based on hospital admission
Blinding (performance bias and detection bias)
All outcomes
Unclear riskDue to the quasi-randomisation method treatment arms cannot be adequately blinded
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskNot described
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot described
Incomplete outcome data (attrition bias)
All outcomes
Unclear risk16% loss to follow-up at 2 years
Selective reporting (reporting bias)Low riskAll data seem reported

Yagishita 2012

MethodsRandomised controlled trial. Method of randomisation, concealment of allocation and blinding not described
Participants

Group A: 29 knees

Group B: 29 knees

29 patients participated; bilateral procedures were studied

Inclusion:

Osteoarthritis bilateral (with the same K&L grade in both knees)

Exclusion:

Osteoarthritis of hip or ankle resulting in restricted walking

Neurological deficits resulting in restricted walking

If an augmentation procedure was necessary

Age: 74.3 ± 7.2 (58 to 91)

Gender (M:F): 4:25 (86% female)

Interventions

Posterior cruciate ligament:

Group A: Retention

Group B: Resection + posterior stabilised

Brand: NexGen (Zimmer, Warsaw, Ind)

Patella: Not described

Bearing: Not described

Cement: Not described

Outcomes

Knee Society Score Clinical
Knee Society Score Functional

Pain (including VAS)

Range of motion

Radiological: radiolucency

Notes

Mean follow-up: 5.0 ± 0.7 (3y to 6y)

Follow-up rate: 90% (at three years after operation)

Ligament balancing in extension and flexion was performed

Funding source: no external funding

Risk of bias
BiasAuthors' judgementSupport for judgement
Random sequence generation (selection bias)Unclear riskSequence generation is not described
Allocation concealment (selection bias)Unclear riskThere is no method described how allocation was concealed, furthermore since surgery was bilateral the allocation of the contralateral knee was never concealed
Blinding (performance bias and detection bias)
All outcomes
Unclear riskNot described
Blinding of participants and personnel (performance bias)
All outcomes
Unclear riskNot described
Blinding of outcome assessment (detection bias)
All outcomes
Unclear riskNot described, radiologically the difference between posterior cruciate retaining and sacrificing implant designs is clear
Incomplete outcome data (attrition bias)
All outcomes
Low risk10% (N = 3) lost to follow-up after 3 years including 1 (N = 3.5%) deceased during follow-up
Selective reporting (reporting bias)Low riskIt seems all outcome measures are reported

Characteristics of excluded studies [ordered by study ID]

StudyReason for exclusion
Aigner 2004Intervention is not focused on retention versus removal of the posterior cruciate ligament. Information could not be extracted adequately
Cope 2002< 12 months follow-up
Husain 1998Conference proceedings
Ishii 2008< 12 months follow-up; latest outcome measure at discharge
Lee 2005Unclear if the study is a randomised trial
MacDonald 2005Conference proceedings
Matsuda 2003Conference proceedings
Matsuda 2005Unclear if the study is a randomised trial
Surace 1997Conference proceedings
Swanik 2004< 12 months follow-up
Yamamoto 2003Conference proceedings

Characteristics of ongoing studies [ordered by study ID]

ACTRN12609000960257

Trial name or titleCruciate retaining versus posterior stabilised total knee replacement: a randomised controlled trial
MethodsRandomised controlled trial
Participants

Target N = 60

Including both osteoarthritis and rheumatoid arthritis

Exclusion criteria:

Tibial deformity (including past fracture or high tibial osteotomy)

Valgus deformity

< 40 years old and > 90 years old

Interventions

Group A: total knee arthroplasty cruciate-retaining

Group B: total knee arthroplasty posterior stabilised

Outcomes

Primary outcome:

Active range of motion measured with goniometer

Oxford Knee Score (knee function)

Secondary outcome:

6 minute walking test

Starting date01/11/2009
Contact informationtibialalignment@gmail.com (Riaz Kahn)
Notes 

ISRCTN05635855

Trial name or titleFunctional outcome in two different designs of knee replacements
MethodsRandomised controlled trial
Participants

Target N = 90

Inclusion criteria:

Osteoarthritis able to flex the knee 90 degrees or more

Exclusion criteria:

Inflammatory poly-arthritis

Disorders of feet, ankles, hips or spine causing abnormal gait or significant pain

Dementia

Severe visual impairment

Neurological conditions affecting movement

Inability to give informed consent

Any other disorders of the contralateral knee causing abnormal gait or significant pain

Interventions

Group A: PFC Sigma (DePuy Int, UK) fixed bearing posterior cruciate ligament preserving arthroplasty

Group B: PFC Sigma (DePuy Int, UK) posterior stabilised mobile bearing arthroplasty

Outcomes

Primary outcome:

Knee excursion during functional activities as measured using electrogoniometry

Secondary outcomes:

Passive knee range of motion

Flexor and extensor strength as measured using a MIE myometer

Knee Society Score

WOMAC total

SF-36 quality of life survey

Pain (visual analogue scale)

Walking speed

Physical activity measured with activity monitor

Canadian Occupational Performance Measure

Starting date01/09/2007
Contact informationmvanderlinden@gmu.ac.uk
NotesFunded by DePuy Int Ltd (UK)

ISRCTN82612978

Trial name or titlePosterior cruciate ligament and total knee arthroplasty: retain, sacrifice or substitute? A prospective, randomised clinical trial
MethodsRandomised controlled trial
Participants

Target N = 285

Inclusion criteria:

Primary osteoarthritis planned for total knee arthroplasty

Operation can be performed using total condylar knee

Collateral (ligaments) are intact

Axis at least one degree varus

Age 18 to 80 years old

Patient speaks Finnish

Exclusion criteria:

Secondary osteoarthritis

Arthroplasty of other knee or of the ankle preceding 12 months

Simultaneous one-stage total knee arthroplasty

Patient has undergone surgery of the other hip, knee or ankle with unsatisfactory outcome

Malignancy

Cortisone or immunosuppressive medication use

Impaired co-operation

Impairment of mobility due to systemic disease

BMI > 40

Fertile women who are planning to give birth during the study

Previous knee surgery (either open or arthroscopic)

Permanent patellar dislocation

Extra-articular deformity

Mechanical axis >15 degrees varus or valgus

Interventions

Group A: Posterior cruciate ligament retaining total knee arthroplasty

Group B: Posterior cruciate ligament excised, but not replaced

Group C: Posterior cruciate ligament excised, and posterior stabilised design

Outcomes

Primary outcome:

Total knee function questionnaire

Visual Analogue Scale for satisfaction (2, 5 and 10 years after surgery)

Secondary outcome:

WOMAC total

20 metre walking test

3 metre up and go test

Quality of life

Oxford Knee Score

Starting date20/04/2006
Contact informationville.remes@hus.fi
Notes 

van den Boom 2009

Trial name or titleRetention of the posterior cruciate ligament versus the posterior stabilised design in total knee arthroplasty: a prospective randomised controlled clinical trial
Methods

Randomised controlled trial.

Group A: Retention of the posterior cruciate ligament

Group B: Resection of the posterior cruciate ligament + posterior stabilised design

ParticipantsTarget N = 120
Interventions

Group A: posterior cruciate ligament retaining

Group B: posterior cruciate ligament sacrificing, posterior stabilised

OutcomesPerceived outcome measures, range of motion, Knee Score, quality of life, gait parameters and femoral rollback
Starting date01-01-2008
Contact informationl.vandenboom@home.nl
NotesNTR (Dutch Trial Registry) 1673

Ancillary