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Femoral nerve blocks for acute postoperative pain after knee replacement surgery

  1. Ee-Yuee Chan1,2,*,
  2. Marlene Fransen1,
  3. David A Parker3,
  4. Pryseley N Assam4,5,
  5. Nelson Chua6

Editorial Group: Cochrane Anaesthesia Group

Published Online: 13 MAY 2014

Assessed as up-to-date: 31 JAN 2013

DOI: 10.1002/14651858.CD009941.pub2


How to Cite

Chan EY, Fransen M, Parker DA, Assam PN, Chua N. Femoral nerve blocks for acute postoperative pain after knee replacement surgery. Cochrane Database of Systematic Reviews 2014, Issue 5. Art. No.: CD009941. DOI: 10.1002/14651858.CD009941.pub2.

Author Information

  1. 1

    University of Sydney, Faculty of Health Sciences, Sydney, NSW, Australia

  2. 2

    Tan Tock Seng Hospital, Nursing Service, Singapore, Singapore

  3. 3

    Sydney Orthopaedic Research Institute, Sydney, NSW, Australia

  4. 4

    Duke-NUS Graduate Medical School, Centre for Quantitative Medicine, Office of Clinical Sciences, Singapore, Singapore

  5. 5

    Singapore Clinical Research Institute Pte Ltd, Department of Biostatistics, Singapore, Singapore

  6. 6

    Tan Tock Seng Hospital, Department of Anaesthesiology, Singapore, Singapore

*Ee-Yuee Chan, eeyuee@gmail.com.

Publication History

  1. Publication Status: New
  2. Published Online: 13 MAY 2014

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Summary of findings    [Explanations]

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review

 
Summary of findings for the main comparison. FNB (any type) compared with PCA opioid for knee replacement surgery

FNB (any type) compared with PCA opioid for knee replacement surgery

Patient or population: patients with knee replacement surgery
Settings: hospital
Intervention: FNB (any type)
Comparison: PCA opioid

OutcomesIllustrative comparative risks* (95% CI)Relative effect
(95% CI)
No. of participants
(studies)
Quality of the evidence
(GRADE)
Comments

Assumed riskCorresponding risk

PCA opioidFNB (any type)

Pain at rest at 24 hours
Visual analogue scale Scale from zero to 10
Follow-up: median two days
Mean pain at rest at 24 hours ranged across control groups from
0.7 to 5.5 points
Mean pain at rest at 24 hours in the intervention groups was 1.20 lower (1.60 to 0.87 lower)1066
(19 studies)
⊕⊕⊕⊝
moderate1
SMD -0.72 (-0.93 to -0.51), representing moderate effects between groups. Lower score indicates less pain2

Pain on movement at 24 hours
Visual analogue scale Scale from zero to 10
Follow-up: median two days
Mean pain on movement at 24 hours ranged across control groups from
2.8 to 8 points
Mean pain on movement at 24 hours in the intervention groups was 1.66 lower (2.32 to 0.97 lower)1017
(17 studies)
⊕⊕⊕⊝
moderate1
SMD -0.94 (-1.32 to -0.55), representing moderate to large effect between groups. Lower score indicates less pain2

Neurological injury
Follow-up: during hospitalization
See commentSee commentNot estimable390
(4 studies)
See commentEffect is uncertain as neurological injuries are extremely rare. No events were reported in four studies

Opioid consumption at 24 hours
using morphine equivalents Scale from zero to 150 mg
Follow-up: 24 hours
Mean opioid consumption 24 hours ranged across control groups from
19.3 to 99.8 mg
Mean opioid consumption at 24 hours in the intervention groups was 14.17 lower (18.10 to 10.23 lower)1156
(20 studies)
⊕⊕⊕⊕
high3
MD -14.74 mg (-18.68 to -10.81 mg)

Nausea and/or vomiting
Follow-up: median two days
Study population4RR 0.47
(0.33 to 0.68)
1100
(16 studies)
⊕⊕⊕⊕
high3

47 per 10022 per 100
(15 to 32)

Low4

10 per 1005 per 100

(3 to 7)

High4

93 per 10044 per 100
(31 to 63)

Knee flexion range of motion
(degree)5
Follow-up: median three days
Mean knee flexion range of motion ranged across control groups from
55 to 85 degrees
Mean knee flexion in the intervention group was 6.48 higher (4.27 to 8.69 higher)596
(11 studies)
⊕⊕⊕⊝
moderate1
MD 6.48 degrees (4.27 to 8.69 degrees)

Participant satisfaction with analgesia
(point)

Scale from zero to 10
Follow-up: during hospitalization
Mean participant satisfaction ranged across control groups from
6.3 to 8.7 points
Mean participant satisfaction was 1.79 higher (1.25 to 2.32 higher)180
(4 studies)
⊕⊕⊝⊝
low6
SMD 1.06 (0.74 to 1.38), representing large effects. Higher score indicates greater satisfaction2

*The basis for the assumed risk (e.g. median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI).
CI: Confidence interval; RR: Risk ratio.

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.

 1Downgraded for significant heterogeneity.
2Rule of thumb for interpreting SMD: 0.2 small effect, 0.5 moderate effect, 0.8 large effect (Cohen 1988).
3Downgrading for significant heterogeneity balanced by upgrading for large effect based on consistent evidence from more than two studies.
4Assumed risk was based on control group risk in the included studies.
5Knee flexion of 90 degrees is usually required for patients to be able to climb stairs.
6Downgraded for relatively few participants and for lack of blinding of participants, personnel and/or outcome assessors in some trials.

 Summary of findings 2 FNB (any type) compared with epidural analgesia for knee replacement surgery

 Summary of findings 3 FNB (any type) compared with local infiltration analgesia for knee replacement surgery

 Summary of findings 4 Continuous FNB compared with single-shot FNB for knee replacement surgery

 

Background

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
 

Description of the condition

Total knee replacement (TKR) is a common orthopaedic operation, consisting of replacing diseased or damaged knee joint surfaces to relieve the pain and disability of osteoarthritis. The significant public health burden of osteoarthritis is reflected in the findings that nearly half of all adults in the United States are at risk of developing symptomatic knee osteoarthritis by 85 years of age (Murphy 2008). The number of knee replacements undertaken annually around the world will increase exponentially as the population ages and becomes more obese. Indeed, the number of primary TKR procedures in the United States was projected to increase almost eight-fold, from 450,000 in 2005 to 3.48 million in 2030 (Kurtz 2007).

TKR is one of the most painful surgical procedures. Effective analgesia in the immediate postoperative phase is important to allow the patient to exercise and regain mobility, thereby facilitating recovery and decreasing the length of hospital stay (Capdevila 1999; Chelly 2001). Unrelieved severe postoperative pain can result in pathophysiological responses causing adverse postsurgical outcomes. These adverse outcomes have medical and economic implications, such as impaired early rehabilitation, delayed discharge, unscheduled rehospitalization, impaired health-related quality of life and increased risk of chronic pain (American Society of Anesthesiologists 2004; Carr 1999; Sinatra 2009; Twersky 1997).

Various analgesic techniques are used to relieve postoperative pain following TKR. Analgesic options include patient-controlled analgesia (PCA) using opioids, epidural analgesia, local infiltration analgesia and femoral nerve block (FNB) with local anaesthetic agents. PCA opioids have been associated with significant adverse effects such as respiratory depression, nausea, urinary retention and constipation (Chelly 2001; Sinatra 2009). Epidural analgesia, when given simultaneously with an anticoagulant, has been associated with spinal epidural haematoma as well as hypotension, urinary retention and pruritus (Capdevila 1999; Choi 2003; Sinatra 2009). Epidural analgesia also causes bilateral motor blockade to the same extent, which may interfere with early mobilization (Barrington 2005). Some randomized controlled trials (RCTs) have suggested that FNB provides better pain control and fewer opioid-related adverse effects compared with PCA opioid or epidural analgesia (Chelly 2001; Sundarathiti 2009; Szczukowski 2004; Wang 2002). Local infiltration analgesia is an emerging technique. The advantage of local infiltration analgesia is that pain conduction is blocked at its origin. A study evaluating the efficacy of a perioperative local infiltration analgesia consisting of local anaesthetic and morphine found a significant reduction in pain and opioid consumption during the first postoperative 48 hours compared with PCA morphine (Vendittoli 2006). To date, no systematic review has compared the effects of FNB with those of local infiltration analgesia.

 

Description of the intervention

Femoral, psoas (lumbar plexus) and fascia iliaca blocks have been used as postoperative analgesic techniques for TKR surgery. Among these nerve blocks, the FNB is used most commonly. An FNB may be given as a single shot or as a continuous block via a catheter and an infusion.

One method that is commonly used to deliver an FNB is the Winnie paravascular technique (Winnie 1973), in which a peripheral nerve stimulator or ultrasound guidance is often used to locate the nerve. When a peripheral nerve stimulator needle is used, the common femoral artery is palpated first with the patient in the supine position, and the stimulating needle is then inserted at the inguinal crease, approximately 1 cm lateral to the femoral artery pulse. Stimulation of the femoral nerve generates contraction of the quadriceps muscle. The needle position is optimised when contractions persist at an output of 0.3 mA to 0.5 mA. Approximately 20 ml to 30 ml of local anaesthetic is then injected. When using ultrasound, the operator places the transducer in the inguinal crease to locate the hyperechoic femoral nerve, which can be visualized lateral to the hypoechoic pulsative common femoral artery. Successful FNB is attained when the local anaesthetic is seen circumferentially around the nerve (Ballantyne 2010).

An FNB can also be performed as part of a more extensive nerve block, termed the three-in-one block (femoral, lateral femoral cutaneous and obturator nerves). In the three-in-one block, a greater volume of local anaesthetic is used, and pressure is applied just distal to the needle during administration of the local anaesthetic to help spread the local anaesthetic to the lateral femoral cutaneous and obturator nerves. However, the femoral nerve is the only nerve that is consistently blocked (Lang 1993). Consequently, the three-in-one block frequently is referred to simply as the FNB (Enneking 2009).

 

How the intervention might work

An FNB blocks sensation to the anteromedial aspect of the knee, thus reducing pain and muscle spasms. Compared with a single shot, continuous FNB provides a longer duration of postoperative analgesia (Sinatra 2009) with a lower concentration of local anaesthetic. These features may allow earlier rehabilitation with a continuous FNB, compared with a single-shot FNB, in that the degree of motor block is reduced. An FNB does not block sensation to the posterior aspect of the knee, as it is innervated by the sciatic nerve. To improve postoperative analgesia, a sciatic and/or obturator nerve blockade is sometimes added to the FNB (McNamee 2002; Morin 2005).

 

Why it is important to do this review

Traditionally, PCA opioid and epidural analgesia were the postoperative analgesic methods of choice following TKR. Recent years have seen a growing interest in the use of FNB to minimize the adverse effects associated with PCA opioid or epidural analgesic techniques. However, FNB after TKR surgery is not without risk; concerns about prolonged quadriceps weakness (Kandasami 2009) and complications such as femoral neuropathy or neuritis have been reported; an increased risk of falls has also been associated with continuous FNB, compared with single-shot block or no block (Feibel 2009; Johnson 2013; Sharma 2010). Additionally, continuous FNB catheters require specialized skills and additional time for insertion and management.

A sciatic nerve block is sometimes combined with an FNB to improve analgesia (Morin 2005). However, this combination could lead to complications such as increased risk of falls and heel ulceration. The combination could also mask peroneal nerve injury or an evolving sciatic nerve injury from compartment syndrome (Ben-David 2004; Kadic 2009; Todkar 2005). A selective obturator nerve block is added at times to an FNB, but the additional analgesic benefit is conflicting (Macalou 2004; McNamee 2002).

To date, no strong evidence has been obtained from large RCTs evaluating the comparative efficacy and safety of FNB versus other forms of postoperative analgesia. A recent systematic review limited to English language publications up to 2009 concluded that single-shot or continuous FNB (with PCA opioid) was superior to PCA opioid alone for acute pain control in the first 72 hours after knee replacement (Paul 2010). Another systematic review compared nerve blockade with epidural analgesia and found no significant difference in pain in the first 24 hours post operation (Fowler 2008). Our work will extend that of these reviews by looking at all comparator analgesic regimens, including the emerging analgesic technique of local infiltration analgesia; by examining outcomes beyond the initial postoperative period and by not limiting our search to English language publications. The rapidly rising number of TKRs performed annually worldwide will considerably increase the burden on healthcare resources (March 2004). A systematic review is needed to evaluate current evidence for the short- and long-term safety and efficacy of FNB after TKR.

 

Objectives

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review

To evaluate the benefits and risks of FNB used as a postoperative analgesic technique relative to other analgesic techniques among adults undergoing TKR..

 

Methods

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
 

Criteria for considering studies for this review

 

Types of studies

We included RCTs comparing FNB (inserted preoperatively, operatively or postoperatively) versus postoperative analgesic techniques not requiring an FNB (intravenous PCA opioids, epidural analgesia, local infiltration analgesia and oral analgesia).

We excluded quasi-randomized trials (e.g. using alternation) and observational studies.

 

Types of participants

We included adults who have undergone TKR surgery.

 

Types of interventions

FNB involving groin injections of any type (performed in isolation or as part of a three-in-one block) used to provide postoperative analgesia after TKR surgery versus no FNB. We also included RCTs that compared continuous versus single-shot FNB.

 

Types of outcome measures

In this review, we intend to examine the following outcomes across a range of potential alternatives to FNB. We will present sequentially all outcomes for each comparison with FNB as follows: (1) PCA opioid; (2) epidural analgesia; (3) local Infiltration analgesia and (4) oral analgesia; we will also compare two types of FNB: (5) continuous FNB versus (6) single-shot FNB.

 

Primary outcomes

1. Pain at rest and on movement

We considered pain at rest and on movement within the following postoperative time frames: first two hours, three to 12 hours, 24 hours, 48 hours, 72 hours and more than 72 hours. Pain outcomes were based on measures with reliable and validated psychometric properties such as the visual analogue scale (VAS). We converted data to a zero to 10 scale. Unless otherwise reported, pain was assumed to be experienced at rest.

2. Serious adverse events

We defined a serious adverse event as any untoward occurrence that results in death, is life threatening, requires rehospitalization or prolongation of existing hospitalisation, results in persistent or significant disability or is considered a medically important event or reaction. Examples include neurological injury, postoperative falls and thrombotic events. We used the time frame set by the study authors.

 

Secondary outcomes

3. Proportion of participants in significant pain postoperatively, as defined by the study authors

4. Time from end of surgery to first rescue analgesic request

5. Opioid consumption

We converted intravenous fentanyl and oral oxycodone to intravenous morphine dosing equivalents using the following computations: 1 mg oral oxycodone = 0.6 mg intravenous morphine; and 1 µg intravenous fentanyl = 0.067 mg intravenous morphine (Allman 2006; Berdine 2006). Data on opioid consumption were expected to be skewed in distribution, and it is recommended that opioid consumption be dichotomised (Moore 2011; PaPaS document 2011). However, opioid consumption was not reported as above or below a certain threshold. Instead, the included studies reported opioid consumption as mean (standard deviation (SD)) milligrams, and we had to follow suit. Some studies reported opioid consumption as cumulative consumption since its commencement, whereas others used consumption over 24 hours. When available, we analysed total cumulative consumption since commencement.

6. Adverse effects

a. Nausea or vomiting, or both, in the first 72 hours. If more than one time point was reported, we chose the data closest to the first 24 hours, when the adverse effects were most pronounced. When both nausea and vomiting were reported, we used the data for vomiting, with the assumption that all participants who vomited would have also experienced nausea. When nausea and vomiting were reported as mild, moderate or severe, the numbers experiencing severe nausea or vomiting were used.

b. Sedation in the first 72 hours using sedation score of at least one on a four-point scale where zero = alert; one = drowsy; two = sleeping, easy to arouse and three = sleeping, difficult to arouse; or using the author's definition of event/no event.

c. Urinary retention requiring catheterization or using the author's definition of event/no event in the first 72 hours.

d. Technical failure of the blocks.

7. Physical function

a. Knee flexion range of motion during the first four postoperative days.

b. Knee extension range of motion during the first four postoperative days.

c. Time to first ambulation during the first four postoperative days.

When more than one time point was reported for range of motion, we chose the time point closest to the fourth day, when ambulation ability is more critical with impending hospital discharge.

8. Participant satisfaction with analgesia during the hospital stay

Participant satisfaction was reported on a continuous scale or as dichotomous data (i.e. number of participants in a study satisfied with treatment). We normalised continuous data to a zero to 10 scale.

 

Search methods for identification of studies

 

Electronic searches

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) 2013, Issue 1 (see Appendix 1); MEDLINE (Ovid SP) (1948 to January 2013) (see Appendix 2); EMBASE (Ovid SP) (1980 to January 2013) (see Appendix 3); CINAHL (EBSCO host) (1982 to January 2013) (see Appendix 4); ISI Web of Science (1973 to January 2013) (see Appendix 5) and dissertation abstracts.

We combined the sensitive strategies suggested in Section 6.4 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011) to search for trials in MEDLINE. We adopted the search strategy for MEDLINE to search all other databases. The search strategies used are reported in Appendices 1 to 5. We applied no language restriction.

 

Searching other resources

One review author (EC) reviewed the references of relevant articles and textbooks for additional citations. We also searched trial registers (www.clinicaltrials.gov, www.controlled-trials.com and http://www.anzctr.org.au), Google Scholar and the Procedure Specific Postoperative Pain Management (PROSPECT) Website (www.postoppain.org) to ensure that significant papers were not missed. The date of the last search was 31 January 2013.

 

Data collection and analysis

 

Selection of studies

Two review authors (EC and MF) independently screened for eligibility the titles and abstracts of publications identified in the literature search.. We obtained and assessed the full published manuscripts of clinical trials that appeared to be eligible to assess their relevance on the basis of prespecified inclusion criteria. Each of these review authors documented the reasons for study exclusion.The fifth review author (NC) resolved disagreements regarding study exclusion. All review authors have participated in trials that could potentially be eligible for this review (see Declarations of interest). To prevent conflict of interest, two independent reviewers (MH and FP; see Acknowledgements) determined the eligibility of these trials.

A copy of the 'Study selection form' is provided in Appendix 6.

 

Data extraction and management

Two review authors (EC and MF) independently performed data extraction using a data extraction form (see Appendix 7). The fifth review author (NC) resolved disagreements. Two independent reviewers extracted the data of an included trial when the review authors were among the study investigators. We contacted trial authors to ask for additional details of their studies.

 

Assessment of risk of bias in included studies

Two review authors (EC and MF) independently assessed the methodological quality of eligible trials using the tool stated in Chapter 8 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011) (see Appendix 8). We resolved disagreements by discussion with the fifth review author (NC). Two independent reviewers assessed the risk of bias of included trials when the review authors were among the study investigators.

In cases of insufficient reporting to enable judgement of 'low risk' or 'high risk,' we contacted the respective study authors to ask for more information. We rated the method as 'unclear' if we could not reach the study authors.

We conducted sensitivity analyses to determine the effect of excluding studies considered to be at high or unclear risk of bias. The results of studies with high and unclear risk of bias were not considered when the results of our sensitivity analyses were interpreted, although we presented them in the meta-analyses for completeness.

 
1. Random sequence generation

We considered random sequence generation as low risk if it was generated by using a computer, by using a random number table algorithm or by drawing lots or shuffling cards.

 
2. Concealment of allocation

We considered allocation concealment as low risk if participant recruiters, investigators and participants were unable to anticipate treatment assignment. Adequate methods included a central allocation system (telephone, Web-based or pharmacy controlled randomisation) or sequentially numbered sealed opaque envelopes.

 
3. Blinding of participants and personnel

We considered blinding as low risk of bias if:

a. participants and personnel (healthcare providers) were blinded to the allocated intervention; and

b. it was unlikely that the blinding could have been broken.

We considered blinding as high risk if:

a. blinding of participants and personnel was attempted, but it was likely that the blinding could have been broken; and

b. no blinding or incomplete blinding was applied.

 
4. Blinding of outcome assessment

We considered blinding as low risk if:

a. outcome assessors were blinded to the allocated intervention, and it was unlikely that the blinding could have been broken.

We considered blinding as high risk if:

a. outcome assessors were blinded, but it was likely that the blinding could have been broken; and

b. outcome assessors were not blinded.

 
5. Incomplete outcome data

We considered a study as having low risk of incomplete outcome data if:

a. no outcome data were missing;

b. the proportion of missing outcomes compared with observed event risks was not enough to have a clinically relevant impact on the intervention effect estimate (i.e. the percentage of missing data was small relative to the incidence proportion of the outcome);

c. reasons for missing outcome data were unlikely to be related to true outcomes and the percentage of missing data was small; and

d. missing outcome data were balanced in quantities across intervention groups with similar reasons for missing data across groups, and the percentage of missing data was small.

A study was considered as having high risk of incomplete outcome data if:

a. reasons for missing outcome data were likely to be related to true outcomes with imbalance in numbers or reasons for missing data across intervention groups;

b. the proportion of missing outcomes compared with the proportion of observed events was enough to induce clinically relevant bias in intervention effect estimates; and

c. 'as treated' analysis was performed with substantial differences between the numbers of participants contributing to the analysis and the numbers of participants randomly assigned.

 
6. Selective reporting

We considered low risk of selective reporting if all of the a priori outcomes of a study that are of interest in the review were reported in the prespecified way.

We considered high risk of selective reporting for any of the following.

a. Not all of the a priori outcomes of a study were reported.

b. One or more primary outcomes were reported using only measurements, analysis methods or subsets of data that were not prespecified.

c. One or more reported primary outcomes were not prespecified, unless clear justification of their reporting was provided.

d. One or more outcomes of interest in the review were reported incompletely and therefore could not be included in a meta-analysis.

 
7. Other sources of bias

We also assessed whether the study used intention-to-treat (ITT) analysis methods (Hollis 1999) for the primary outcomes.

 

Measures of treatment effect

We calculated risk ratios (RRs) with 95% confidence intervals (CIs) for dichotomous outcomes and mean differences (MDs) or standardized mean differences (SMDs) with 95% CIs for continuous outcomes. For comparisons based on continuous outcomes consisting of trials that reported only differences between groups, we converted the data for all relevant trials to estimate the intervention effect and its corresponding standard error (Borenstein 2009) and used generic inverse variance outcome type. A similar approach was used for comparisons including RCTs that reported a zero SD in one of the intervention arms.

For continuous outcomes, we interpreted intervention effects based on SMDs according to the rule of thumb where 0.2 or smaller represents a small effect, 0.5 a moderate effect and 0.8 or larger a large effect (Higgins 2011; see Section 12.6.2). To further assist in interpreting SMDs, we reexpressed them in their original units by multiplying the pooled SMD with the pooled SD of the control group differences (Higgins 2011; see Section 12.6.4).

SMD is a more sensible measure for synthesizing pain outcomes because one cannot verify whether 2-cm changes in VAS are equivalent across the scale. Thus the combination of VAS results that have sampled different parts of the scale might be misrepresented by combining MDs and might be better represented by using SMDs. We have used SMDs to report the outcome of participant satisfaction (measured using scale zero to 10) for the same reason..

We calculated number needed to treat for an additional beneficial outcome (NNTB) or an additional harmful outcome (NNTH) as and where appropriate. We obtained confidence intervals for NNTB/NNTH by inverting and exchanging the confidence limits for the absolute risk reduction (ARR). We used the Wilson score method to calculate the confidence limits of ARR and NNTB/NNTH (Bender 2001; Wilson 1927).

 

Unit of analysis issues

Some RCTs had three or four allocation groups. When the study contributed several independent comparisons (e.g. FNB vs PCA and FNB vs epidural), the interventions were analysed separately in the appropriate meta-analyses as if they were from different studies.

When the RCTs contributed several correlated comparisons, with similar type of FNB (e.g. continuous FNB with ropivacaine vs PCA and continuous FNB with bupivacaine vs PCA), to the same meta-analysis, we combined the groups to create a single pair-wise comparison, as recommended in Chapter 16 of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011).

If the RCTs contributed several correlated comparisons, with different types of FNB (e.g. single-shot FNB vs PCA and continuous FNB vs PCA) to a meta-analysis, we split the control group into two groups (shared) and included two 'reasonably independent' comparisons. This was done to address the issues of double-counting and unit of analysis errors in the control group (Higgins 2011; see Chapter 16).

 

Dealing with missing data

We contacted the study authors if any required data were missing or unclear.

We calculated the missing estimates of SDs from other relevant statistics reported in the study (e.g. standard error, 95% CI, P value). If these statistics were reported, the missing SDs were imputed according to the recommendations of the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011; see Chapter 16) using the RevMan calculator. Some studies presented results using a combination of median, interquartile range (25th and 75th quartiles) and/or range (minimum and maximum values). We calculated corresponding means and SDs from the presented results based on the recommendation of Hozo 2005. The required data were estimated as follows.

Mean = (Minimum + 2 * Median + Maximum)/4, if median and range were reported for each group; otherwise, Mean = Median.

SD = SQRT (1/12(((Min - 2 * Median + Max)2)/4 + (Min - Max)2), if group size was less than 15 and median and range were reported for each group.

SD = SQRT((Min – Max)/4), if the range was reported and the group size was greater than 15 but equal to or less than 70.

SD = SQRT((Min – Max)/6), if the range was reported and the group size was greater than 70.

SD = (75th Quartile – 25th Quartile)/1.35, if the interquartile range was reported.

 

Assessment of heterogeneity

We assessed heterogeneity of included RCTs on the basis of their clinical and methodological diversity (risk of bias assessment). Our a priori hypothesis for sources of clinical heterogeneity were as follows.

  1. Different analgesic regimens (e.g. FNB as single-shot or continuous infusion, using different types of local anaesthetics, concentrations, infusion rates and timings of injections; and with or without sciatic or obturator nerve blocks).
  2. Different standard co-analgesic regimens.

We presented primary analyses using the random-effects model to account for the impact of anticipated clinical and methodological heterogeneity. We assessed statistical heterogeneity using the Chi2 test for heterogeneity and quantified heterogeneity using the I2 statistic (Higgins 2011). We considered values of I2 greater than 50% to represent significant between-study heterogeneity (Higgins 2003). If significant heterogeneity was demonstrated, we explored the data to test whether our planned subgroup analyses explained this heterogeneity.

 

Assessment of reporting biases

We used Orwin's fail-safe N test to evaluate the impact of potential publication bias on the robustness of the overall observed analgesic effect (Orwin 1983). We determined how many missing studies without an intervention effect (magnitude of SMD ≤ 0.01) would render a significant overall or pooled effect non-significant or trivial. The trivial effect was defined by an SMD value of 0.2 (Orwin 1983).

 

Data synthesis

We conducted a meta-analysis using Review Manager 5.2 (RevMan 5.2) when data from two or more RCTs were sufficient. We used the random-effects model of DerSimonian and Laird, as we anticipated that heterogeneity would be present in the interventions and in the outcomes (DerSimonian 1986).

VAS results that sampled different parts of the scale were combined using SMDs. As the dichotomous data for opioid consumption were not available, the means of opioid consumption were synthesized using SMDs. When it was not possible to conduct a meta-analysis, we discussed the results narratively.

Primary analyses include the following.

  1. Single-shot or continuous FNB (± sciatic/obturator block ± PCA opioid) versus PCA opioid.
  2. Single-shot or continuous FNB (± sciatic/obturator block) versus epidural analgesia.
  3. Single-shot or continuous FNB versus local infiltration analgesia.
  4. Single-shot or continuous FNB versus oral analgesia.
  5. Continuous versus single-shot FNB.

We stratified the meta-analyses of included RCTs according to type of FNB (single-shot FNB, single-shot FNB + sciatic block, single-shot FNB + obturator block, continuous FNB, continuous FNB + sciatic block). For subgroup and sensitivity analyses, we combined the various types of FNB.

We did not adjust for multiplicity of the multiple primary analyses as, in general, this is not recommended (see Section 16.7.2 of the Cochrane Handbook for Systematic Reviews of Interventions) (Higgins 2011).

 

Subgroup analysis and investigation of heterogeneity

We limited subgroup and sensitivity analyses to the outcomes of pain at rest and on movement at 24 hours.

We performed the following subgroup analyses.

  1. Type of FNB (i.e. single-shot FNB and continuous FNB, with or without an additional sciatic/obturator nerve block).
  2. FNB (any type) with or without a concurrent parenteral opioid.
  3. Type of local anaesthetic (i.e. FNB (any type) using ropivacaine and FNB (any type) using bupivacaine).

 

Sensitivity analysis

We performed sensitivity analyses to evaluate the effect on the overall primary result of removing trials with low and unclear methodological quality (i.e. allocation concealment, as well as blinding of participants, personnel and outcome assessors). We did not conduct sensitivity analyses to determine the effect of missing data imputation, as no substantial missing data issues were identified in the included RCTs. Also, sensitivity analysis based on multiple interventions within studies was not performed because we followed the recommendations provided in the Cochrane Handbook for Systematic Reviews of Interventions (see Chapter 16; Higgins 2011), as discussed in the Unit of analysis issues section.

 
Summary of findings tables

We used the principles of the GRADE system (Guyatt 2008) to assess the quality of the body of evidence associated with specific outcomes (pain at rest at 24 hours, pain on movement at 24 hours, neurological injury, opioid consumption at 24 hours, nausea and/or vomiting, knee flexion range of motion, participant satisfaction with analgesia) in our review, and we constructed a 'Summary of findings' (SoF) table using the GRADE software (see Appendix 9). The GRADE approach appraises the quality of a body of evidence based on the extent to which one can be confident that an estimate of effect or association reflects the item being assessed. The quality of a body of evidence considers within-study risk of bias (methodological quality), directness of the evidence, heterogeneity of the data, precision of effect estimates and risk of publication bias (see Chapter 12) (Higgins 2011).

 

Results

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
 

Description of studies

See Characteristics of included studies and Characteristics of excluded studies.

 

Results of the search

Figure 1 shows the results of the literature search. We identified 87 publications for potential inclusion, of which we excluded 36 after reviewing the full-text reports and assigned as awaiting assessment to four conference abstracts. We identified 45 eligible RCTs from 47 publications (two sets of publications reported the same randomized trials (Bergeron 2009 and Kardash 2007; Seet 2006 and Shum 2009). We managed to contact 21 authors of the included studies to clarify the study methodology or to obtain additional data (three of the authors no longer have the original data).

 FigureFigure 1. Study flow diagram.

 

Included studies

We included 45 RCTs with a total of 2710 participants. Details of the individual RCTs are provided in the Characteristics of included studies table. Three RCTs were reported in Chinese (Tang 2010; Wang 2010; Yu 2010), and one RCT was published in German (Fritze 2009). Two RCTs (Chan 2013; Widmer 2012), for which some of the review authors were named, were judged eligible for inclusion by two independent reviewers (MH and FP). In two RCTs (Martin 2008; Mistraletti 2006), the effects of FNB on inflammation and postoperative suppression of gluconeogenesis, respectively, were the main focus of the studies.

The sample size of the individual RCTs ranged from 18 (Ng 2012) to 200 (Chan 2013) participants, the age of study participants ranged from 29 to 86 years (Affas 2011) and the proportion of female participants ranged from 38% (Good 2007) to 100% (Park 2010).

Of the included RCTs, 20 (Adams 2002; Allen 1998; Chan 2012; Chan 2013; de Lima e Souza 2008; Fritze 2009; Ganapathy 1999; Hirst 1996; Hunt 2009; Kaloul 2004; Kardash 2007; Macalou 2004; McNamee 2001; Mistraletti 2006; Ng 2001; Park 2010; Seet 2006; Singelyn 1998; Tugay 2006; Xie 2012) evaluated more than two treatment groups (see Unit of analysis issues section).

In three of these RCTs, one of the treatment groups was excluded from the review because it was a non-randomized group (Hunt 2009) or because the treatment did not meet the review's inclusion criteria (psoas block group in Kaloul 2004; obturator block group in Kardash 2007).

The included RCTs made the following comparisons according to the aims of this review.

1. FNB (with or without PCA opioid) versus PCA opioid (29 RCTs with two RCTs having three allocation groups)

Of the included RCTs, 14 (Adams 2002; Allen 1998; Chan 2012; Chan 2013; Good 2007; Hirst 1996; Hunt 2009; Kardash 2007; Macalou 2004; Ng 2001; Ozen 2006; Szczukowski 2004; Tugay 2006; Wang 2002) compared single-shot FNB versus PCA.

Two RCTs (Allen 1998; McNamee 2001) compared single-shot FNB + sciatic block versus PCA, and one RCT (Macalou 2004) compared single-shot FNB + obturator versus PCA.

Of the included RCTs, 12 (Baranovic 2011; Chan 2013; Ganapathy 1999; Hirst 1996; Kadic 2009; Kaloul 2004; Seet 2006; Serpell 2001; Singelyn 1998; Tang 2010; Wang 2010; Yu 2010) compared continuous FNB versus PCA.

Two RCTs (Martin 2008; Mistraletti 2006) compared continuous FNB + sciatic versus PCA.

All except six RCTs (Adams 2002; Baranovic 2011; Chan 2013; Mistraletti 2006; Singelyn 1998; Yu 2010) had a concurrent PCA opioid in the FNB intervention.

2. FNB versus epidural analgesia (10 RCTs with one RCT contributing two comparisons)

One RCT (Adams 2002) compared single-shot FNB versus epidural, and another RCT (Davies 2004) compared single-shot FNB + sciatic versus epidural. One RCT (Lee 2011) compared single-shot FNB + epidural versus epidural; the results of this study were not pooled, as a concurrent epidural was included in the FNB intervention.

Five RCTs (Barrington 2005; Fritze 2009; Long 2006; Singelyn 1998; Sundarathiti 2009) compared continuous FNB versus epidural.

Three RCTs (Fritze 2009; Mistraletti 2006; Zaric 2006) compared continuous FNB + sciatic versus epidural.

3. FNB versus local infiltration analgesia (six RCTs)

One RCT (Parvataneni 2007) compared single-shot FNB versus local infiltration analgesia.

Three RCTs (Affas 2011; Carli 2010; Toftdahl 2007) compared continuous FNB versus local infiltration analgesia.

One RCT (Widmer 2012) compared single-shot FNB + local infiltration analgesia versus local infiltration analgesia alone; the results of this study were not pooled, as a concurrent local infiltration analgesia was included in the FNB intervention.

One cross-over RCT (Ng 2012) with knees as the unit of comparison compared continuous FNB versus local infiltration analgesia. The data from this RCT were not included in the meta-analysis, as we were uncertain about the cross-over effects and issues with analysis.

4. FNB versus oral analgesia (one RCT)

One RCT (Nader 2012) compared continuous FNB + oral analgesia versus oral analgesia.

5. Continuous FNB versus single-shot FNB (four RCTs)

Four RCTs (Chan 2013; Hirst 1996; Park 2010; Salinas 2006) made the comparison between continuous and single-shot FNB. Three of these studies (Hirst 1996; Park 2010; Salinas 2006) had a concurrent PCA opioid intervention in both the continuous and single-shot FNB groups, and one study (Chan 2013) had a concurrent PCA opioid intervention only in the single-shot FNB group.

 

Excluded studies

We excluded 36 trials for the reasons given in the Characteristics of excluded studies. We assigned four trials reported as conference abstracts as awaiting assessment as they do not contain enough information to allow determination of eligibility, or they do not provide quantifiable outcome data (Characteristics of studies awaiting classification).

 

Risk of bias in included studies

The risk of bias assessment for the individual RCTs is shown in the 'Risk of bias' graph and the 'Risk of bias' summary in Figure 2 and Figure 3, respectively. Details are provided in the risk of bias tables in the Characteristics of included studies.

 FigureFigure 2. Risk of bias summary: review authors' judgements about each risk of bias item for each included study.
 FigureFigure 3. Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.

 

Allocation

All studies stated that the participants were randomly allocated to treatment groups. The method of randomization was judged to have a low risk of bias for 33 (73%) RCTs and unclear risk for 12 (27%) RCTs, as the methods were not stated and we were unable to reach the study authors for details.

Concealment of allocation was adequate in 28 (62%) and unclear in 17 (38%) included RCTs. Concealment using sealed envelopes without mention of whether they were sequentially numbered and opaque was rated unclear.

 

Blinding

Blinding of participants and personnel was judged to be at low risk of bias for 17 (38%) RCTs, high risk of bias for 17 (38%) RCTs and unclear risk of bias for 11 (24%) RCTs. Twenty RCTs (44%) reported using blinded outcome assessors, 18 (40%) RCTs did not blind outcome assessors and seven (16%) RCTs were judged as having unclear risk, as they provided no information on assessor blinding.

 

Incomplete outcome data

The short follow-up period (first 72 hours post operation) in most of the RCTs reduced the risk of loss to follow-up. Hence, attrition bias was low in all except four (9%) RCTs (Long 2006; Park 2010; Seet 2006; Xie 2012), which were rated as unclear, as no information on post randomization exclusions was provided. Two (4%) RCTs (Baranovic 2011; Zaric 2006) were rated as high risk, as 18% to 20% post randomization exclusions were determined. See Characteristics of included studies.

 

Selective reporting

We judged that selective reporting bias was avoided by the reporting of results for all outcomes listed in the methods section and by the provision of additional data on request. The risk of reporting bias was low to moderate for the included RCTs.

 

Other potential sources of bias

All RCTs except two (4%) (Baranovic 2011; Zaric 2006) had a low risk of bias for intention-to-treat analysis, as the number of participants lost to follow-up for the outcomes of interest in this review was very small.

 

Effects of interventions

See:  Summary of findings for the main comparison FNB (any type) compared with PCA opioid for knee replacement surgery;  Summary of findings 2 FNB (any type) compared with epidural analgesia for knee replacement surgery;  Summary of findings 3 FNB (any type) compared with local infiltration analgesia for knee replacement surgery;  Summary of findings 4 Continuous FNB compared with single-shot FNB for knee replacement surgery

See Data and analyses;  Summary of findings for the main comparison (FNB with or without PCA opioid vs PCA opioid);  Summary of findings 2 (FNB vs epidural);  Summary of findings 3 (FNB vs local infiltration analgesia) and  Summary of findings 4 (continuous vs single-shot FNB).

For pain and participant satisfaction outcomes, we interpreted intervention effects based on SMDs according to the rule of thumb where 0.2 or smaller represents a small effect, 0.5 a moderate effect and 0.8 or larger a large effect (Higgins 2011; see Section 12.6.2).

 

I. FNB (with or without PCA opioid) versus PCA opioid

 

Primary outcomes

 

1. Pain at rest and on movement

(See  Analysis 1.1;  Analysis 1.2;  Analysis 1.3;  Analysis 1.4;  Analysis 1.5;  Analysis 1.6;  Analysis 1.7; Figure 4;  Analysis 1.9;  Analysis 1.10.)

 FigureFigure 4. Forest plot of comparison: 1 FNB versus PCA opioid. Outcome: 1.8 Pain on movement at 24 hours.

Pooled results for FNB (any type, with or without a concurrent PCA opioid) vs PCA opioid demonstrated significantly lower pain at rest for FNB from zero to 72 hours: first two hours (11 RCTs, 706 participants, SMD -0.58, 95% CI -1.00 to -0.16, I2 = 84%), three to 12 hours (14 RCTs, 972 participants, SMD -0.97, 95% CI -1.42 to -0.52, I2 = 89%), 24 hours (19 RCTs, 1066 participants, SMD -0.72, 95% CI -0.93 to -0.51, I2 = 54%), 48 hours (17 RCTs, 957 participants, SMD -0.64, 95% CI -1.03 to -0.25, I2 = 86%), and 72 hours (eight RCTs, 560 participants, SMD -0.67, 95% CI -1.32 to -0.01, I2 = 92%).

Similarly, the pooled results for pain on movement also demonstrated significantly less pain for FNB (any type, with or without a concurrent PCA opioid) from zero to 48 hours: first two hours (four RCTs, 218 participants, SMD -1.29, 95% CI -2.12 to -0.46, I2 = 84%), three to 12 hours (eight RCTs, 462 participants, SMD -1.06, 95% -1.68 to -0.43, I2 = 88%), 24 hours (17 RCTs, 1017 participants, SMD -0.94, 95% CI -1.32 to -0.55, I2 = 86%) and 48 hours (13 RCTs, 742 participants, SMD -0.44, 95% CI -0.71 to -0.16, I2 = 65%). The results for 72 hours also favoured FNB, although not significantly (six RCTs, 438 participants, SMD -0.17, 95% CI -0.39 to 0.04, I2 = 11%).

Three RCTs (264 participants) (Chan 2013; Martin 2008; Mistraletti 2006) assessed pain intensity after 72 hours. Of these, one RCT (Chan 2013) compared continuous FNB (catheter duration less than 72 hours) and single-shot FNB with PCA, and two RCTs (Martin 2008; Mistraletti 2006) compared continuous FNB + sciatic versus PCA (catheter duration 48 hours). Chan 2013 found no significant difference in pain scores at rest and on movement at day five, week two and month three; Mistraletti 2006 reported no difference in pain at rest on discharge between the allocation groups. Martin 2008 reported significantly less pain at rest for FNB at day seven, but not at month one and month three, compared with PCA opioid.

For pain at rest and on movement at 48 hours, the result of test for differences between subgroups is statistically significant (P < 0.05), suggesting that analgesic effects at 48 hours are not consistent between the different types of FNB subgroups.

Pain at rest and on movement at 24 hours: subgroup analysis by type of FNB

(See  Analysis 1.3;  Analysis 1.8.)

We categorised RCTs according to type of FNB (i.e. single-shot FNB, single-shot FNB + sciatic/obturator block, continuous FNB, continuous FNB + sciatic block). For the single-shot FNB subgroup, pain at rest at 24 hours (nine RCTs, 416 participants, SMD -0.65, 95% CI -1.08 to -0.22, I2 = 75%) and pain on movement at 24 hours (six RCTs, 287 participants, SMD -0.50, 95% CI -0.81 to -0.19, I2 = 29%) were significantly less in the FNB subgroup compared with PCA. Pain scores were also significantly lower in the continuous FNB subgroup at rest at 24 hours (10 RCTs, 578 participants, SMD -0.74, 95% CI -0.97 to -0.51, I2 = 27%) and on movement at 24 hours (10 RCTs, 584 participants, SMD -1.09, 95% CI -1.74 to -0.43, I2 = 92%).

Only a few small RCTs evaluated the addition of sciatic or obturator block to the single-shot or continuous FNB. The single-shot FNB + sciatic block subgroup had significantly lower pain scores compared with the PCA opioid subgroup on movement at 24 hours (two RCTs, 92 participants, SMD -0.73, 95% CI -1.18 to -0.29, I2 = 0%) but not at rest at 24 hours (one RCT, 24 participants, SMD -0.73, 95% CI -1.74 to 0.28). The continuous FNB + sciatic block subgroup favoured FNB for pain at rest at 24 hours (two RCTs, 54 participants, SMD -0.85, 95% CI -1.55 to -0.15, I2 = 28%) but not for pain on movement at 24 hours (two RCTs, 54 participants, SMD -2.08, 95% CI -4.74 to 0.58, I2 = 90%).

Generally, results of the subgroup analyses demonstrated that the type of FNB explained some of the heterogeneity of the overall results (I2 < 30% for continuous FNB and continuous FNB + sciatic block for pain at rest at 24 hours; and I2 < 30% for single-shot FNB and single-shot FNB + sciatic block for pain on movement at 24 hours).

Results of the various types of FNB at other timings are shown in these analyses (see  Analysis 1.4;  Analysis 1.5;  Analysis 1.9;  Analysis 1.10).

Pain at rest and on movement at 24 hours: subgroup analysis by FNB with and without concurrent PCA opioid

(See  Analysis 1.11;  Analysis 1.12.)

For pain at rest at 24 hours, FNB (any type) both with a concurrent PCA opioid (15 RCTs, 771 participants, SMD -0.67, 95% CI -0.94 to -0.41, I2 = 65%) and without a concurrent PCA opioid (five RCTs, 295 participants, SMD -0.93, 95% CI -1.31 to -0.55, I2 = 43%) demonstrated significantly less pain compared with PCA opioid alone. Similarly, for pain on movement at 24 hours, the groups given FNB with a concurrent PCA opioid (14 RCTs, 802 participants, SMD -0.67, 95% CI -0.99 to -0.35, I2 = 76%) and without a concurrent PCA opioid (four RCTs, 215 participants, SMD -2.26, 95% CI -3.95 to -0.57, I2 = 95%) had significantly less pain when compared with the group given PCA opioid alone.

Pain at rest and on movement at 24 hours: subgroup analysis by FNB with ropivacaine versus bupivacaine

(See  Analysis 1.13;  Analysis 1.14.)

For pain at rest at 24 hours, both FNB (any type) with ropivacaine (eight RCTs, 379 participants, SMD -1.30, 95% CI -2.03 to -0.58, I2 = 90%) and FNB (any type) with bupivacaine (11 RCTs, 649 participants, SMD -0.61, 95% CI -0.89 to -0.33, I2 = 61%) demonstrated significantly less pain compared with PCA opioid. For pain on movement at 24 hours, the group given FNB with ropivacaine (eight RCTs, 409 participants, SMD -0.98, 95% CI -1.67 to -0.29, I2 = 90%) and FNB with bupivacaine (10 RCTs, 632 participants, SMD -0.92, 95% CI -1.39 to -0.44, I2 = 85%) also had significantly less pain compared with the group given PCA opioid.

This subgroup analysis did not explain the heterogeneity in the main results.

Pain at rest and on movement at 24 hours: sensitivity analysis by adequacy of allocation concealment and blinding

(See  Analysis 1.15;  Analysis 1.16;  Analysis 1.17;  Analysis 1.18.)

Pooling only the RCTs with low risk of bias regarding allocation concealment showed a significant reduction in the FNB (any type) for pain at rest (nine RCTs, 523 participants, SMD -0.54, 95% CI -0.76 to -0.32, I2 = 28%) and on movement (nine RCTs, 583 participants, SMD -0.54, 95% CI -0.75 to -0.33, I2 = 30%) at 24 hours.

Pooling only the results of trials with low risk of bias for adequate blinding of participants, personnel and outcome assessors also demonstrated significantly less pain at rest at 24 hours (seven RCTs, 319 participants, SMD -0.62, 95% CI -1.08 to -0.17, I2 = 71%) and on movement at 24 hours (seven RCTs, 356 participants, SMD -0.57, 95% CI -0.79 to -0.35, I2 = 0). Heterogeneity was explained by adequate blinding for pain on movement but not at rest at 24 hours.

 

2. Serious adverse events

Few RCTs reported on serious adverse events.

Five RCTs (474 participants) reported no neurological injury in the FNB group (Chan 2012; Chan 2013; Kadic 2009; McNamee 2001; Seet 2006). Persistent numbness of the anterior thigh at 48 hours was reported in one participant in the single-shot FNB group compared with none in the PCA opioid group (one RCT, 40 participants) (Kardash 2007). One RCT (42 participants) reported that in the single-shot FNB group, a participant had knee numbness, and in the PCA group, two participants had infection and one participant had dyspnoea (Good 2007). The only RCT (200 participants) that reported on thrombotic events had one event in the continuous FNB group (Chan 2013). Two RCTs (282 participants) reported no falls in the FNB or PCA group (during the hospital stay (Chan 2013) or during the first three postoperative days (Chan 2012)). Three RCTs (192 participants) reported that no local anaesthetic toxicity was noted in the FNB or PCA group (Kadic 2009; McNamee 2001, Seet 2006). Five RCTs reported on technical failure: 27% technical failure with continuous FNB 0.2% bupivacaine and 55% with continuous FNB 0.1% bupivacaine in one RCT (62 participants) (Ganapathy 1999), no technical failure with the continuous FNB in one RCT (58 participants) (Kadic 2009) and no technical failure with the single-shot FNB in three RCTs (171 participants) (Allen 1998; de Lima e Souza 2008; McNamee 2001).

 

Secondary outcomes

 

1. Proportion of participants with significant pain postoperatively

Six comparisons from five RCTs (511 participants) reported the proportion of participants with moderate/severe pain. FNB demonstrated significantly fewer participants with moderate/severe pain compared with PCA opioid (RR 0.73, 95% CI 0.65 to 0.82, I2 = 0). The NNTB was five (95% CI four to 11).

 

2. Time from end of surgery to first rescue opioid request

Two RCTs (Chan 2012; McNamee 2001) reported that participants receiving single-shot FNB took significantly longer time to first opioid request compared with those receiving PCA. One RCT (McNamee 2001) (74 participants, MD 7.21 hour, 95% CI 6.88 to 7.54 hour) demonstrated a much larger FNB effect compared with the other (Chan 2012) (82 participants, MD 3.23 hour, 95% CI 1.88 to 4.58 hour). The former RCT (McNamee 2001) had the addition of a sciatic block. The findings of these two RCTS were not pooled because of the high heterogeneity (I2 = 99%).

 

3. Opioid consumption

(See  Analysis 1.19;  Analysis 1.20.)

Pooled results for opioid consumption (IV morphine equivalent) were significantly reduced for FNB at 24 hours (20 RCTs, 1152 participants, MD -14.74 mg, 95% -18.68 to -10.81 mg, I2 = 88%) and at 48 hours (19 RCTs, 1001 participants, MD -14.53 mg, 95% -20.03 to -9.02 mg, I2 = 88%).

 

4. Adverse effects

 

4.1 Nausea and/or vomiting

(See  Analysis 1.21.)

Pooled results showed that the risk of nausea and/or vomiting was significantly lower for FNB compared with PCA opioid (16 RCTs, 1100 participants, RR 0.47, 95% CI 0.33 to 0.68, I2 = 73%). The NNTH was four (95% CI three to six).

 

4.2 Sedation

(See  Analysis 1.22.)

Pooled results showed that the risk of sedation was significantly lower in the FNB group as compared with the PCA opioid group (nine RCTs, 808 participants, RR 0.34, 95% CI 0.16 to 0.74, I2 = 85%; NNTH five, 95% CI five to eight).

 

4.3 Urinary retention

(See  Analysis 1.23.)

Seven RCTs with 37 events from 490 participants evaluated urinary retention. These results showed no difference in risk of urinary retention between FNB and PCA opioid (RR 0.57, 95% CI 0.20 to 1.68, I2 = 40%).

 

5. Physical function

(See  Analysis 1.24.)

During postoperative day two to four, the FNB group achieved greater knee flexion (10 RCTs, 541 participants, MD 6.48 degrees, 95% CI 4.27 to 8.69 degrees, I2 = 79%) and knee extension (three RCTs, 297 participants, MD -0.16 degrees, 95% CI -0.30 to -0.01 degrees, I2 = 0%) compared with the PCA opioid group. Two RCTs evaluated time to first ambulation and found no differences between groups (71 participants, MD 1.86 degrees, 95% CI -7.40 to 11.12 degrees, I2 = 0%).

 

6. Participant satisfaction with analgesia during hospital stay

(See  Analysis 1.25.)

Four studies assessed participant satisfaction on a continuous scale, and their pooled results indicated greater participant satisfaction with FNB versus PCA opioid (180 participants, SMD 1.06, 95% CI 0.74 to 1.38, I2 = 0%). Two small RCTs reported participant satisfaction as a dichotomous variable, and their results were not pooled because of high heterogeneity (I2 = 96%). The findings of both studies were not statistically significant (42 participants, RR 1.00, 95% CI 0.91 to 1.09) (Adams 2002); (62 participants, RR 1.64, 95% CI 1.02 to 2.64) (de Lima e Souza 2008).

 

II. FNB versus epidural analgesia

 

Primary outcomes

 

1. Pain at rest and on movement

(See  Analysis 2.3;  Analysis 2.5.)

We found no differences in pooled pain scores at rest and on movement for all measured time points in the first 72 hours post operation between FNB and epidural analgesia. Pooled results for FNB (any type) versus epidural for pain at rest at 24 hours included the following: six RCTs, 328 participants, SMD -0.05, 95% CI -0.43 to 0.32, I2 = 61%; and for pain on movement at 24 hours: six RCTs, 317 participants, SMD 0.01, 95% CI -0.21 to 0.24, I2 = 0%. The data from one study with a concurrent epidural in the FNB intervention showed significantly lower pain scores for the FNB + epidural intervention for pain on movement at 24 hours compared with epidural alone (78 participants, SMD -2.94, 95% CI -3.59 to -2.29) but not for pain at rest at 24 hours (SMD -0.34, 95% CI -0.79 to 0.10) (Lee 2011). Details of the pooled results at rest at two hours, three to 12 hours and 48 hours are shown in  Analysis 2.1;  Analysis 2.2;  Analysis 2.4 and  Analysis 2.6. The other non-significant findings were for pain at rest at 72 hours (two RCTs, 124 participants, SMD 0.18, 95% CI -0.35 to 0.71, I2 = 45%); pain on movement at three to 12 hours (one RCT, 59 participants, SMD 0.20, 95% CI -0.31 to 0.71) and pain on movement at 72 hours (one RCT, 54 participants, SMD 0.61, 95% CI -0.06 to 1.09).

The test results for subgroup differences were significant (P < 0.05) for pain at rest at two hours and at three to 12 hours,

Pain at rest and on movement at 24 hours: subgroup analysis by type of FNB

(See  Analysis 2.3; Figure 5.)

 FigureFigure 5. Forest plot of comparison: 2 FNB versus epidural. Outcome: 2.5 Pain on movement at 24 hours.

No significant differences were detected between pain scores at rest and on movement at 24 hours for the subgroups of single-shot FNB + sciatic block, continuous FNB and continuous FNB + sciatic block. For pain at rest at 24 hours, statistical heterogeneity was reduced in the analyses by type of FNB for the continuous FNB + sciatic block subgroup (three RCTs, 93 participants, SMD 0.09, 95% CI -0.32 to 0.51, I2 = 0%). For pain on movement at 24 hours, no heterogeneity was found (I2 = 0%) in the subgroups of continuous FNB (three RCTs, 165 participants, SMD 0.12, 95% CI -0.19 to 0.43) and continuous FNB + sciatic block (three RCTs, 93 participants, SMD 0.06, 95% CI -0.36 to 0.47). Only one RCT was identified in the subgroup of. single-shot FNB + sciatic block (59 participants, SMD -0.33, 95% CI -0.85 to 0.18) for this outcome.

Pain at rest and on movement at 24 hours: subgroup analysis by FNB with ropivacaine versus bupivacaine

(See  Analysis 2.7;  Analysis 2.8.)

For pain at rest at 24 hours, no significant differences were detected for FNB with ropivacaine (four RCTs, 190 participants, SMD -0.16, 95% CI -0.68 to 0.37, I2 = 65%) or FNB with bupivacaine (two RCTs, 216 participants, SMD 0.20, 95% CI -0.13 to 0.53, I2 = 0%) compared with epidural, respectively. Similarly, for pain on movement at 24 hours, no significant differences were found for FNB with ropivacaine (four RCTs, 120 participants, SMD 0.10, 95% CI -0.27 to 0.47, I2 = 0%) or FNB with bupivacaine (three RCTs, 197 participants, SMD -0.03, 95% CI -0.31 to 0.25, I2 = 0%) compared with epidural, respectively.

Pain at rest and on movement at 24 hours: sensitivity analysis by adequacy of allocation concealment and blinding

(See  Analysis 2.9;  Analysis 2.10.)

No significant difference between the groups was detected at 24 hours on the basis of pooled results from RCTs with low risk of bias for allocation concealment for pain at rest (three RCTs, 194 participants, SMD 0.20, 95% CI -0.07 to 0.47, I2 = 0%) and for pain on movement (four RCTs, 271 participants, SMD 0.03, 95% CI -0.21 to 0.27, I2 = 0%). Statistical heterogeneity was reduced in analyses by adequate allocation concealment for pain at rest and on movement at 24 hours. Sensitivity analysis on the adequacy of blinding was not conducted, as no RCTs with low risk of bias for blinding were identified.

 

2. Serious adverse events

Four RCTs reported on neurological injury: One RCT (59 participants) reported that a participant with epidural developed unilateral foot drop and sphincteric disturbance after operation, but the aetiology was not stated (Davies 2004), and three RCTs (247 participants) reported no incidence of neurological injury in either allocation group (Barrington 2005; Lee 2011; Sundarathiti 2009). One RCT (70 participant) with a follow-up of six months post operation reported a participant with a fall at home with wound dehiscence requiring reoperation in the continuous FNB group and none in the epidural group (Long 2006). This RCT also reported two participants in the continuous FNB group requiring close manipulation, one participant in the epidural group with bladder inflammation from reaction to latex of the Foley catheter and no incidence of haematoma formation of the knee or drainage in either group (Long 2006). Another RCT (50 participants) reported a participant with atrial fibrillation in the epidural group (Zaric 2006). There was no incidence of local anaesthetic toxicity from two RCTs (111 patients) (Sundarathiti 2009; Zaric 2006), and no incidence of catheter-related infection from one RCT (61 patients) (Sundarathiti 2009). One RCT (108 patients) reported three cardiac events (one non-ST elevation myocardiac infarction and one cardiac conduction defect requiring permanent pacemaker) in the continuous FNB group and one hypotension (60/40 mmHg and bradycardic,spinal-epidural block reached dermatome T3 upon 2 hours of the epidural infusion) in the epidural group (Barrington 2005). Another RCT (59 patients) reported frequent hypotension in both allocation groups (37% in the single-shot FNB+sciatic group and 27% in the epidural group) (Davies 2004). Conversely, another RCT (78 patients) reported no incidence of severe hypotension or cardiac complications (Lee 2011).

 

Secondary outcomes

 

1. Proportion of participants with significant pain postoperatively

The result from one small RCT (61 participants) favoured epidural between groups for the proportion of participants with moderate/severe pain (RR 2.07, 95% CI 1.28 to 3.33) (Sundarathiti 2009).

 

2. Time from end of surgery to first rescue analgesic request

We found no data on this outcome.

 

3. Opioid consumption

(See  Analysis 2.11;  Analysis 2.12.)

Results from five RCTs indicate that the FNB group consumed less opioid (IV morphine equivalent) compared with the epidural group at 24 hours (341 participants, MD -4.35 mg, 95% CI -9.95 to 1.26 mg, I2 = 50%). Similarly, pooled results at 48 hours also favoured FNB (four RCTs, 233 participants, MD -1.28 mg, 95% CI -5.30 to 2.74 mg, I2 = 0%), although this finding was not statistically significant.

We did not pool the data from three RCTs because the data at 24 and 48 hours were not available (Barrington 2005; Sundarathiti 2009) or because the analgesics were too varied (Singelyn 1998). In the first RCT (108 participants) (Barrington 2005), over 72 hours, the continuous FNB group required less morphine (mean (SD) 44 (30) vs 53 (28) mg, P value 0.45), but more oxycodone (mean (SD) 21 (15) vs 13 (12) mg, P value 0.005) compared with the epidural group. However the epidural group also received a mean dosage of fentanyl of 1.74 mg. In the second RCT (61 participants) (Sundarathiti 2009), the cumulative IV tramadol over 72 hours was higher in the continuous FNB group compared with the epidural group (median (range) = 150 (0 to 350) vs 50 (0 to 150) mg, P value 0.001). In the third RCT (30 participants) (Singelyn 1998), both the FNB and epidural groups received infusion bupivacaine with sufentanil and clonidine, and the supplemental analgesics required in the first 48 hours were comparable (propacetamol 1.7 (1.1) vs 1.1 (1.5) g, P value 0.37; IM piritramide 1.9 (4.1) vs 2.3 (6.2) mg, P value 0.29).

 

4. Adverse effects

 

4.1 Nausea and/or vomiting

(See  Analysis 2.13.)

Pooled results from four RCTs demonstrated that the risk of nausea and/or vomiting in the FNB group was less than in the epidural group (183 participants, RR 0.63, 95% CI 0.41 to 0.97, I2 = 0%). The NNTH was eight, 95% CI four to 53.

 

4.2 Sedation

The only RCT that evaluated sedation found no significant difference in risk of sedation between the allocation groups (50 participants, RR 0.43, 95% CI 0.04 to 4.40) (Zaric 2006).

 

4.3 Urinary retention

Pooled results from four RCTs revealed no significant difference between groups in risk of urinary retention (200 participants, RR 0.36, 95% CI 0.07 to 1.88, I2 = 49%).

 

4.4 Technical failure of the blocks

The meta-analysis of four RCTs (287 participants) found no difference in technical failure of the block (RR 0.87, 95% CI 0.49 to 1.55, I2 = 0%) or catheter disconnection/problem (RR 0.73, 95% CI 0.24 to 2.22, I2 = 15%) between the FNB and epidural groups.

 

5. Physical function

Pooled data of six RCTs revealed no significant difference in knee flexion during postoperative day two to four (328 participants, MD -1.65 degrees, 95% CI -5.14 to 1.84 degrees, I2 = 33%), and the results from one RCT (Long 2006) showed no significant difference in knee extension on postoperative day three between groups (115 participants, MD 5.00 degrees, 95% CI 1.62 to 8.38 degrees).

One small RCT evaluated the time to first ambulation and found no differences between groups (16 participants, MD 8.50 hours, 95% CI -5.50 to 22.50 hours) (Mistraletti 2006).

 

6. Participant satisfaction with analgesia

Two RCTs reported on participant satisfaction as a continuous variable (scale zero to 10), and their pooled results indicate that participants with FNB were more satisfied (120 participants, SMD 0.60, 95% CI 0.23 to 0.97, I2 = 0%). The only RCT that evaluated participant satisfaction as a dichotomous outcome reported that all participants in both FNB and epidural groups were satisfied with their treatment (30 participants, RR 1, 95% CI 0.91 to 1.09) (Singelyn 1998).

 

III. FNB versus local infiltration analgesia

 

Primary outcomes

 

1. Pain at rest and on movement

(See  Analysis 3.1;  Analysis 3.2;  Analysis 3.3;  Analysis 3.4.)

Pooled results revealed no difference between FNB and local infiltration analgesia for pain at rest at 24 hours (four RCTs, 216 participants, SMD 0.06, 95% CI -0.61 to 0.72, I2 = 82%) and at 48 hours (two RCTs, 114 participants, SMD -0.26, 95% CI -0.94 to 0.43, I2 = 68%) or for pain on movement at 24 hours (three RCTs, 153 participants, SMD 0.38, 95% CI -0.10 to 0.86, I2 = 53%) and at 48 hours (two RCTs, 111 participants, SMD -0.14, 95% CI -0.71 to 0.43, I2 = 54%).

One RCT with FNB + local infiltration analgesia versus local infiltration analgesia also found no difference in pain at rest at 24 hours between allocation groups (55 participants, SMD -0.11, 95% CI -0.64 to 0.42) (Widmer 2012). Similarly, one cross-over RCT (16 participants) comparing collateral knees reported no significant differences between FNB and local infiltration analgesia for pain at rest and on movement at 24 hours, 48 hours and 72 hours (Ng 2012). One RCT assessed pain at rest at 12 hours and found that local infiltration analgesia yielded lower pain scores compared with FNB (76 participants, SMD 0.56, 95% CI 0.10 to 1.02) (Toftdahl 2007).

Pain at rest and on movement at 24 hours: sensitivity analysis by adequacy of blinding

Only one small RCT (40 participants) described adequate blinding of participants, personnel and outcome assessors for pain at rest and on movement at 24 hours (Carli 2010). The RCT favoured FNB for pain at rest at 24 hours (SMD -1.12, 95% CI -1.79 to -0.45) but not for pain on movement at 24 hours (SMD 0.26, 95% CI -0.37 to 0.88).

 

2. Serious adverse event

One RCT (76 participants) reported the following adverse events in the local infiltration group (40 participants) and none in the FNB group: two participants requiring open surgical intervention (one for deep surgical site infection and another for tissue necrosis), two participants with a cardiac event (one syncopal attack of cardiac origin and one episode of chest pain justifying investigation), two participants with gastric ulcer and two participants with urinary tract infection (Toftdahl 2007). Another RCT (40 participants) reported that one participant in the local infiltration group had a cardiac event (atrial fibrillation requiring treatment) (Carli 2010). Four RCTs (171 participants) reported no incidence of neurological injury, wound infection, surgical intervention, cardiac events or falls in both FNB and infiltration groups (Affas 2011; Ng 2012; Parvataneni 2007; Widmer 2012).

 

Secondary outcomes

 

1. Proportion of participants with significant pain postoperatively

No statistical significance was detected in the proportion of participants with moderate/severe pain from the pooling of two RCTs (114 participants, RR 1.86, 95% CI 0.50 to 6.92, I2 = 45%).

 

2. Time from end of surgery to first rescue analgesic request

We found no data on this outcome.

 

3. Opioid consumption

At 24 hours, a small RCT found that FNB had lower opioid consumption compared with local infiltration analgesia, but the results were not significant (40 participants, MD -11.50 mg, 95% CI -24.08 mg to 1.08) (Carli 2010). Another RCT found that FNB + local infiltration analgesia resulted in lower opioid consumption at 24 hours compared with local infiltration analgesia alone (55 participants, MD -35.44 mg, 95% CI -56.02 to -14.86 mg) (Widmer 2012). These two RCTs were not pooled, as one of them (Widmer 2012) had a concurrent local infiltration analgesia in the FNB group. At 48 hours, pooled results of two RCTs on opioid consumption revealed no significant differences (117 participants, MD 3.51 mg, 95% CI -23.43 to 30.46 mg). Similarly, one cross-over RCT (16 participants) reported no significant differences in opioid consumption on postoperative day one or day two between the allocation groups (Ng 2012).

 

4. Adverse effects

 

4.1 Nausea and/or vomiting

(See  Analysis 3.5.)

Pooled results of three RCTs showed no statistical differences between groups in risk of nausea and vomiting (177 participants, RR 1.71, 95% CI 0.64 to 4.62, I2 = 47%).

 

5. Physical function

One RCT found no significant differences in knee flexion on postoperative day two between groups (40 participants, MD -0.50 degrees, -5.28 to 4.28 degrees) (Carli 2010). Another RCT failed to find any significant difference between groups in knee extension on postoperative day two (76 participants, MD 1.15 degrees, 95% CI -1.73 to 4.03 degrees) (Toftdahl 2007).

 

6. Participant satisfaction with analgesia

One RCT found that participants with FNB had lower satisfaction scores compared with participants with local infiltration analgesia (60 participants, mean 7.8 vs 9.0, SD not reported) (Parvataneni 2007).

 

IV. FNB versus oral analgesia

 

Primary outcomes

 

1. Pain at rest and on movement

Only one RCT (62 participants) compared FNB versus oral analgesia. In this RCT (Nader 2012), continuous FNB + oral analgesia was compared with oral analgesia alone on postoperative day one at discontinuation of the epidural analgesia. Investigators found that continuous FNB + oral analgesia led to significantly lower pain scores at rest at 24 hours (MD -3.03, 95% CI -4.00 to -2.06) and 48 hours (MD -2.00, 95% CI -3.20 to -0.80), as well as on movement at 24 hours (MD -2.00, 95% CI -3.10 to -0,90), when compared with oral analgesia alone (Nader 2012). At 72 hours, no significant difference was detected for pain at rest (MD -1.00, 95% CI -2.18 to 0.18).

 

2. Serious adverse event

Following epidural, four of 31 participants in the oral opioid analgesia group had deep venous thrombosis or pulmonary embolus versus none in the continuous FNB + oral analgesia group (Nader 2012).

 

Secondary outcomes

Results from one RCT (62 participants) showed that following epidural, the FNB + oral analgesia group consumed less opioid at 24 hours (MD -15.00 mg, 95% CI -24.50 to -5.50 mg) and at 48 hours (MD -7.00 mg, 95% CI -21.25 to 7.25 mg), although the results were not statistically significant. FNB + oral analgesia also led to greater knee flexion compared with oral analgesia alone (MD 15.00 mg, 95% CI 5.96 to 24.04 mg). However, no significant difference was detected in participant satisfaction between FNB + oral analgesia and oral analgesia alone (MD 2.00 mg, 95% CI 1.06 to 2.94 mg) (Nader 2012). We found no data on the other secondary outcomes.

 

V. Continuous versus single-shot FNB

 

Primary outcomes

 

1. Pain at rest and on movement

(See  Analysis 4.1;  Analysis 4.2;  Analysis 4.3;  Analysis 4.4; Figure 6;  Analysis 4.6.)

 FigureFigure 6. Forest plot of comparison: 4 Continuous FNB versus single-shot FNB. Outcome: 4.5 Pain on movement at 24 hours.

Continuous FNB showed significantly lower pain intensity when compared with single-shot FNB at rest at 24 hours (four RCTs, 272 participants, SMD -0.62, 95% CI -1.17 to -0.07, I2 = 73%) and at 48 hours (four RCTs, 272 participants, SMD -0.96, 95% CI -1.69 to -0.22, I2 = 84%), as well as on movement at 24 hours (four RCTs, 272 participants, SMD -0.42, 95% CI -0.67 to -0.17, I2 = 0%) and at 48 hours (four RCTs, 272 participants, SMD -0.54, 95% CI -1.02 to -0.06, I2 = 65%).

Pooled results of two RCTs (156 participants) at the following time points found no significant differences between allocation groups: pain at rest at two hours (SMD 0.15, 95% CI -0.17 to 0.46, I2 = 0), at three to 12 hours (SMD -0.03, 95% CI -0.35 to 0.28, I2 = 0) and at 72 hours (SMD 0.10, 95% CI -0.21 to 0.42, I2 = 0); and pain on movement at 72 hours (SMD -0.09, 95% CI -0.41 to 0.22, I2 = 0).

Pain at rest and on movement at 24 hours: subgroup analysis by continuous FNB with and without a PCA opioid intervention

(See  Analysis 4.7;  Analysis 4.8.)

For pain at rest at 24 hours, pooled RCTs with a concurrent PCA opioid intervention in both continuous and single-shot FNB groups (three RCTs, 138 participants, SMD -0.86, 95% CI -1.35 to -0.38, I2 = 36%) and the one RCT with a concurrent PCA opioid intervention only in the single-shot FNB group (134 participants, SMD -0.16, 95% CI -0.50 to 0.18), respectively, showed that continuous FNB resulted in less pain compared with single-shot FNB. For pain on movement at 24 hours, results for continuous FNB with a concurrent PCA opioid (three RCTs, 138 participants, SMD -0.59, 95% CI -0.96 to -0.22, I2 = 0) and without a concurrent PCA opioid (one RCT, 134 participants, SMD -0.27, 95% CI -0.61 to 0.07), respectively, also showed continuous FNB to lead to less pain compared with single-shot FNB.

Pain at rest and on movement at 24 hours: sensitivity analysis by adequacy of allocation concealment and blinding

(See  Analysis 4.9;  Analysis 4.10.)

Pooling of only RCTs with low risk of bias for allocation concealment did not change the magnitude or the direction of the effect estimate for pain at 24 hours, at rest (three RCTs, 250 participants, SMD -0.73, 95% CI -1.41 to -0.04, I2 = 82%) or on movement (three RCTs, 250 participants, SMD -0.47, 95% CI -0.79 to -0.15, I2 = 25%).

Only one small RCT (Hirst 1996) (22 participants) had low risk of bias pertaining to blinding. Results indicated that differences between groups for pain at 24 hours were not statistically significant at rest (MD -0.50, 95% CI -2.25 to 1.25) and on movement (MD -0.70, 95% CI -3.09 to 1.69).

 

2. Serious adverse events

Two RCTs (170 participants) that compared continuous versus single-shot FNB reported no incidence of neurological injury (Chan 2013; Salinas 2006). One RCT (38 participants) reported no catheter-related infection (Salinas 2006).

 

Secondary outcomes

 

1. Proportion of participants in significant pain postoperatively

We found no data on this outcome.

 

2. Time from end of surgery to first rescue analgesic request

We found no data on this outcome.

 

3. Opioid consumption

(See  Analysis 4.11;  Analysis 4.12.)

Opioid consumption was significantly less in the continuous FNB group compared with the single-shot FNB group at 24 hours (three RCTs, 236 participants, MD -13.81 mg, 95% CI -23.27 to -4.35 mg, I2 = 88%) and at 48 hours (four RCTs, 269 participants, MD -14.59 mg, 95% CI -22.35 to -6.82 mg, I2 = 75%).

 

4. Adverse effects

 

4.1 Nausea and/or vomiting

Pooled results from two RCTs showed no differences in risk of nausea/vomiting between continuous and single-shot FNB groups (214 participants, RR 0.55, 95% CI 0.20 to 1.56, I2 = 78%).

 

4.2 Sedation

Two RCTs (214 participants) presented results on sedation (Chan 2013; Park 2010). One of these RCTs (134 participants) reported zero events in both groups and did not contribute to the analysis (Chan 2013). Thus, only the results of one RCT were considered; these revealed no differences in risk of sedation between groups (80 participants, RR 4.33, 95% CI 0.60 to 31.07) (Park 2010).

 

4.3 Technical failure of the blocks

One RCT (36 participants) reported that no technical failure occurred (Salinas 2006).

 

5. Physical function

We found no data on this outcome.

 

6. Participant satisfaction with analgesia

We found no data on this outcome.

 

Discussion

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
 

Summary of main results

This review has examined the published evidence comparing the use of FNB (any type) with or without concurrent treatments including PCA opioid versus a variety of alternative methods for reducing postoperative pain following knee replacement surgery. We found that pain at rest and pain on movement were less for FNB at all time intervals considered up to 72 hours post operation. At 24 hours, FNB (any type) had a moderate to large analgesic effect at rest and on movement compared with PCA. The moderate to large effects (SMD), when reexpressed as mean differences (zero to 10 scale), represented at 24 hours a 1.20-point decrease in mean pain at rest and a 1.66-point decrease in mean pain on movement for FNB compared with PCA ( Summary of findings for the main comparison). FNB also resulted in less opioid consumption at 24 hours and 48 hours, and correspondingly lower risk of nausea/vomiting or sedation, compared with PCA opioid.

When compared with an epidural block, no differences in pain at rest or on movement were noted when FNB was used, although FNB demonstrated lower opioid consumption at 24 hours, lower risk of nausea and/or vomiting and greater participant satisfaction compared with epidural. Similarly, no differences were detected between FNB and local infiltration analgesia for pain at rest and on movement at any evaluated time point.

The single study comparing FNB versus oral analgesia after TKR suggested that the former offered superior analgesia at rest from 24 to 48 hours, and on movement at 24 hours.

Using a continuous FNB was superior to using a single-shot technique, with moderate effects on pain intensity noted at 24 hours and 48 hours both at rest and on movement. Reexpressing SMD as MD on a zero to 10 scale suggests, at 24 hours, a 0.95-point reduction in mean pain at rest and a 0.74-point reduction in mean pain on movement ( Summary of findings 4). Continuous FNB also led to lower opioid consumption at 24 hours and at 48 hours compared with single-shot FNB.

Serious adverse events are rare with FNB, and we have been unable to report definitive results concerning the risk of serious adverse events for any of the analgesic techniques examined. Nevertheless, the adverse events in the local infiltration analgesia group reported by Toftdahl 2007 are a cause of concern. Larger trials examining two main issues are needed before this technique can be recommended. First, two reinterventions out of 40 participants for infection or tissue necrosis at the surgical site seems unusually high. Second, although blood concentrations have been reported to be low, the total amount of local anaesthetic administered with this technique is high. Cardiac toxicity in patients with underlying cardiac disease may occur with blood concentrations that would be well tolerated in normal patients. In the RCT, two participants given local infiltration analgesia had cardiac events (Toftdahl 2007). Therefore, before widespread use of this technique is considered, especially in centres with very short hospital stays (less than 24 hours), studies evaluating the effects of this technique on cardiac conduction may be warranted.

 

Overall completeness and applicability of evidence

Generally, application of the review's finding to clinical practice is possible, as adequate descriptions of inclusion and exclusion criteria were provided. Nevertheless, the included RCTs have variable reporting or inconsistent definitions for some of the secondary outcomes. Subgroups involving single-shot or continuous FNB with the addition of sciatic or obturator block should be interpreted cautiously because of the small numbers of trials and participants. For relatively uncommon events such as urinary retention, differences between groups would have been difficult to detect. Additionally, serious adverse events were rare, were reported in very few RCTs and most often were reported anecdotally.

In this review, the overall summary effects of FNB compared with PCA opioid, epidural or local infiltration analgesia, respectively, were derived from the combination of data from any type of FNB including single-shot FNB, if the data were derived from similar postoperative periods. Since the effects of the single-shot FNB possibly last less than 24 hours, the magnitude of the overall summary effect of the FNB (any type) after 24 hours likely underestimates the intervention effect of the continuous FNB.

 

Quality of the evidence

Generally, most RCTs were at low to moderate risk of bias for the aspects rated in our risk of assessment tool, except for the aspect of blinding (see Figure 3). We rated 14 (31%) RCTs at high risk for both participant and assessor blinding, and eight (18%) RCTs were rated at high risk for one blinding aspect. The high risk of bias for blinding was expected, as the nature of the analgesic regimens in this review is such that it is challenging to implement blinding effectively. To do so would have required the insertion of sham catheters. Even with sham catheters, clinical signs of numbness of the affected areas would have broken the blinding to participants. The open-label nature of some of the RCTs may potentially bias the measurement of subjective outcomes such as pain and participant satisfaction.

For allocation concealment, sensitivity analyses pooling only RCTs at low risk of bias demonstrated that the primary results for comparisons of FNB (with or without PCA opioid) versus PCA opioid, FNB versus epidural and continuous FNB versus single-shot FNB were robust. Pooling only RCTs at low risk of bias for blinding of participants/personnel and outcome assessors also showed the findings to be robust for the comparison of FNB versus PCA opioid. As expected, pooling results of trials with low risk of bias resulted in a slight reduction of the magnitude of the mean intervention effect but no change in statistical significance. We were unable to assess the effect of blinding for the comparison of FNB versus epidural, as all included RCTs were at high risk of blinding bias. We also could not conduct sensitivity analyses for the other comparisons because of the limited number of available RCTs.

 

Potential biases in the review process

Publication bias

We may have missed trials that were not indexed in CENTRAL, MEDLINE, EMBASE, CINAHL or Web of Science or that remain unpublished in journals. The fail-safe N test indicated that our results were robust to publication bias (see Appendix 10). Nonetheless, we did approach trialists for information on existing RCTs. Although the possibility of publication bias cannot be excluded, a well-conducted non-significant trial would have had a reasonable chance of being published. The procedure we used to retrieve all RCTs was comprehensive and systematic, and two review authors conducted independent selection from results obtained by the searches. Thus the risk of publication bias is low.

Pooling and heterogeneity

We pooled data from RCTs testing the same comparisons (i.e. FNB vs PCA opioid, FNB vs epidural and FNB vs local infiltration analgesia) and presented the meta-analyses stratified by different types of FNB (single-shot or continuous FNB, with or without sciatic/obturator block). Notable differences were reported in the analgesic regimen across pooled FNB subgroups such as FNB with different local anaesthetics, drug concentrations and infusion rates; control groups with variations in drugs and dosages and differences in the supplemental analgesics used in these trials. These differences likely contributed to high heterogeneity in many of the meta-analyses in this review. The type of FNB and the methodological quality of the trials have explained some of the heterogeneity of pooled data.

We used the random-effects model to account for the anticipated heterogeneity of included RCTs. We also used risk ratios rather than odds ratios to report dichotomous outcomes. These decisions resulted in more conservative estimates of treatment effects with wider confidence intervals, compared with outcomes when fixed-effect models and odds ratios were used. We did not reanalyse the data using a fixed-effect model because of the high heterogeneity of the included trials. Sensitivity analyses demonstrated that the primary findings were robust to potentially influential allocation concealment and blinding bias.

Small-study effects

We did not assess the influence of small trials on estimated treatment effects. Nevertheless, given that all the RCTs included in this review had fewer than 100 participants per arm, small-study effects could potentially have biased the results of meta-analyses towards an inflated treatment effect (Nuesch 2010).

 

Agreements and disagreements with other studies or reviews

The conclusions of the current review are similar to those provided by a previously published meta-analysis comparing FNB and opioids (Paul 2010). Both reviews found single-shot FNB to lead to lower pain scores during movement at 24 hours and at 48 hours; lower opioid requirement at 24 hours and at 48 hours and lower risk of nausea and vomiting. Unlike Paul's review, the current review also found that single-shot FNB and continuous FNB have lower pain intensity at rest at 24 hours and 48 hours, lower risk of sedation, greater knee range of motion and higher participant satisfaction. Both Fischer 2008 and the authors of the current review found single-shot or continuous FNB to have superior effects on pain up to 48 hours. The current review also demonstrated that FNB reduced the risk of nausea and/or vomiting, although this outcome was not significant in the Fischer 2008 review. Additionally, we demonstrated that continuous FNB was superior to single-shot FNB for postoperative analgesia and opioid consumption, unlike in Paul 2010..

Any discordance with the two past reviews (Fischer 2008; Paul 2010) may be due to the fact that the current review included a larger number of RCTs for meta-analysis and therefore had a greater possibility of detecting statistical significance. Moreover, for the continuous versus single-shot FNB comparisons, we conducted direct (head-to-head) comparisons of parallel trials, while Paul 2010 used an indirect comparison.

Another review compared continuous peripheral nerve block and opioids (Richman 2006). That review concluded that continuous peripheral nerve block provided superior postoperative analgesia compared with opioids at 24 hours, 48 hours and 72 hours. It also reported that nerve block led to fewer minor complications, including nausea or vomiting, pruritus and sedation, and improved participant satisfaction. These conclusions were similar to ours, despite the broader inclusion criteria provided in the review by Richman 2006, which extended inclusion to both upper and lower extremity operations, and catheter locations in places other than the femoral nerve.

Our results for FNB versus epidural were somewhat in agreement with those of Fowler 2008, who compared FNB and epidural analgesia for major knee surgery. Both reviews found no differences in pain scores in the first 48 hours, or in physical activities, between FNB and epidural. Both reviews also found that participant satisfaction was greater with FNB compared with epidural analgesia. In contrast to Fowler 2008, our review additionally demonstrated lower opioid consumption at 24 hours and lower risk of nausea and/or vomiting in the FNB group. These differing results could have resulted from differences in the participant populations (TKR compared with major knee surgery).

 

Authors' conclusions

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review

 

Implications for practice

This review found evidence that following TKR, FNB (with or without concurrent treatments including PCA opioid) provided superior analgesia compared with PCA opioid alone, similar analgesia compared with epidural and less nausea/vomiting compared with both PCA opioid alone and epidural analgesia. The review also found that continuous FNB provided a better analgesia and adverse effects profile compared with single-shot FNB. The analgesic benefits of FNB over PCA are moderate to large, and those of continuous FNB over single-shot FNB are small to moderate (Cohen 1988). These findings favour the use of FNB, in particular continuous FNB, over PCA opioid or epidural. The analgesic benefit offered by FNB, however, did not appear to extend beyond the first 72 hours.

We do not have enough evidence in this review to draw conclusions about the additional analgesic benefit of adding sciatic or obturator nerve blocks to the FNB, although results suggest that little analgesic benefit is gained by the addition of the sciatic block. Nevertheless, it was not the intent of this review to compare FNB + sciatic or FNB + obturator versus FNB. Any effects of FNB on serious adverse events were unclear because of the limited available evidence. Information from the identified RCTs was insufficient for definitive conclusions to be drawn on the comparisons between FNB and local infiltration analgesia or oral analgesia.

 
Implications for research

The findings of this review on local infiltration analgesia and oral analgesia were based on the results of a few small RCTs. More RCTs comparing FNB and local infiltration analgesia are warranted, given the increasing popularity of the latter and the increasing number of total knee replacement operations conducted annually worldwide. One problem of the existing evidence involves the varied components of the local infiltration analgesia used in the different studies, making it unclear which particular components of the technique are the determinants of any observed effects. The consistent components have been the local anaesthetic (with ropivacaine or bupivacaine) and epinephrine, although in varying dosages. Conversely, the roles of the other components such as ketorolac, morphine and corticosteroid are less clear, and great variance in usage has been noted between studies. Moreover, safety concerns regarding surgical site infection or tissue necrosis have arisen, along with occurrences of cardiac toxicity in cardiac patients with the use of local infiltration analgesia. Hence, an important area for research is to determine the ideal components and safety of local infiltration analgesia. Indeed, large prospective observational studies are needed to quantify the risk of serious adverse events associated with the local infiltration analgesia.

 

Acknowledgements

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review

We would like to thank Associate Prof Mike Bennett (content editor), Prof Nathan Pace (statistical editor), Prof Joanne Guay, Prof Andrew Moore (peer reviewers) and Dr Janet Wale (consumer editor) for help and editorial advice provided during the preparation of this systematic review.

We would like to thank Dr John Carlisle (content editor), Dr Marialena Trivella (statistical editor), Prof Nathan Pace (co-ordinating editor); Prof Joanne Guay, Prof Andrew Moore, Dr Gustavo Zanoli and Associate Prof Fiona Blyth (peer reviewers) and Dr Janet Wale and Suzanne Cunliffe (consumers) for help and editorial advice provided during the preparation of this systematic review protocol. We also thank the CARG Trials Search Co-ordinator, Dr Karen Hovhannisyan, for help with the search strategy, and the Managing Editor, Mrs Jane Cracknell, for efficient administrative support.

We would like to thank the 21 study authors who responded to our request for additional information, including three authors who regretted that the data were no longer available. We are grateful to Dr Markus Huebscher (MH) and Fereshteh Pourkazemi (FP) for determining the study inclusion and extracting data from studies for which the review authors are the named authors, Isabel Ng HL and Dr Zhang Jinbin for their help in extracting data from the Chinese studies (Tang 2010; Wang 2010; Yu 2010) and Dr Markus Huebscher for extracting data from the German study (Fritze 2009).

 

Data and analyses

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
Download statistical data

 
Comparison 1. FNB versus PCA opioid

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Pain at rest first 2 hours11Std. Mean Difference (Random, 95% CI)-0.58 [1.00, -0.16]

    1.1 Single-shot FNB vs PCA opioid
7Std. Mean Difference (Random, 95% CI)-0.44 [-1.16, 0.28]

    1.2 Single-shot FNB + obturator vs PCA opioid
1Std. Mean Difference (Random, 95% CI)-1.25 [-1.92, -0.57]

    1.3 Continuous FNB vs PCA opioid
5Std. Mean Difference (Random, 95% CI)-0.62 [-1.25, 0.00]

    1.4 Continuous FNB + sciatic vs PCA opioid
1Std. Mean Difference (Random, 95% CI)-0.63 [-1.63, 0.38]

 2 Pain at rest 3 to 12 hours14972Std. Mean Difference (IV, Random, 95% CI)-0.97 [-1.42, -0.52]

    2.1 Single-shot FNB vs PCA opioid
8388Std. Mean Difference (IV, Random, 95% CI)-0.66 [-1.20, -0.11]

    2.2 Single-shot FNB + sciatic vs PCA opioid
118Std. Mean Difference (IV, Random, 95% CI)-1.38 [-2.48, -0.27]

    2.3 Single-shot FNB + obturator vs PCA opioid
147Std. Mean Difference (IV, Random, 95% CI)-0.37 [-1.01, 0.26]

    2.4 Continuous FNB vs PCA opioid
8519Std. Mean Difference (IV, Random, 95% CI)-1.29 [-2.06, -0.52]

 3 Pain at rest 24 hours19Std. Mean Difference (Random, 95% CI)-0.72 [-0.93, -0.51]

    3.1 Single-shot FNB vs PCA opioid
9Std. Mean Difference (Random, 95% CI)-0.65 [-1.08, -0.22]

    3.2 Single-shot FNB + sciatic vs PCA opioid
1Std. Mean Difference (Random, 95% CI)-0.73 [-1.74, 0.28]

    3.3 Continuous FNB vs PCA opioid
10Std. Mean Difference (Random, 95% CI)-0.74 [-0.97, -0.51]

    3.4 Continuous FNB + sciatic vs PCA opioid
2Std. Mean Difference (Random, 95% CI)-0.85 [-1.55, -0.15]

 4 Pain at rest 48 hours17957Std. Mean Difference (IV, Random, 95% CI)-0.64 [-1.03, -0.25]

    4.1 Single-shot FNB vs PCA opioid
9416Std. Mean Difference (IV, Random, 95% CI)-0.38 [-0.83, 0.07]

    4.2 Single-shot FNB + sciatic vs PCA opioid
118Std. Mean Difference (IV, Random, 95% CI)0.21 [-0.77, 1.20]

    4.3 Continuous FNB vs PCA opioid
9507Std. Mean Difference (IV, Random, 95% CI)-0.89 [-1.58, -0.20]

    4.4 Continuous FNB + sciatic vs PCA opioid
116Std. Mean Difference (IV, Random, 95% CI)-1.96 [-3.21, -0.71]

 5 Pain at rest 72 hours8560Std. Mean Difference (IV, Random, 95% CI)-0.67 [-1.32, -0.01]

    5.1 Single-shot FNB vs PCA opioid
5272Std. Mean Difference (IV, Random, 95% CI)-0.26 [-0.61, 0.08]

    5.2 Continuous FNB vs PCA opioid
4250Std. Mean Difference (IV, Random, 95% CI)-1.24 [-3.07, 0.60]

    5.3 Continuous FNB + sciatic vs PCA opioid
138Std. Mean Difference (IV, Random, 95% CI)-0.56 [-1.21, 0.09]

 6 Pain on movement first 2 hours4218Std. Mean Difference (IV, Random, 95% CI)-1.29 [-2.12, -0.46]

    6.1 Single-shot FNB vs PCA opioid
298Std. Mean Difference (IV, Random, 95% CI)-0.85 [-1.27, -0.43]

    6.2 Continuous FNB vs PCA opioid
3120Std. Mean Difference (IV, Random, 95% CI)-1.60 [-3.39, 0.19]

 7 Pain on movement 3 to 12 hours8Std. Mean Difference (Random, 95% CI)-1.06 [-1.68, -0.43]

    7.1 Single-shot FNB vs PCA opioid
2Std. Mean Difference (Random, 95% CI)-1.22 [-1.66, -0.79]

    7.2 Single-shot FNB + sciatic vs PCA opioid
1Std. Mean Difference (Random, 95% CI)-0.34 [-0.83, 0.15]

    7.3 Continuous FNB vs PCA opioid
6Std. Mean Difference (Random, 95% CI)-1.18 [-2.13, -0.23]

 8 Pain on movement 24 hours17Std. Mean Difference (Random, 95% CI)-0.94 [-1.32, -0.55]

    8.1 Single-shot FNB vs PCA opioid
6Std. Mean Difference (Random, 95% CI)-0.50 [-0.81, -0.19]

    8.2 Single-shot FNB + sciatic vs PCA opioid
2Std. Mean Difference (Random, 95% CI)-0.73 [-1.18, -0.29]

    8.3 Continuous FNB vs PCA opioid
10Std. Mean Difference (Random, 95% CI)-1.09 [-1.74, -0.43]

    8.4 Continuous FNB + sciatic vs PCA opioid
2Std. Mean Difference (Random, 95% CI)-2.08 [-4.74, 0.58]

 9 Pain on movement 48 hours13742Std. Mean Difference (IV, Random, 95% CI)-0.44 [-0.71, -0.16]

    9.1 Single-shot FNB vs PCA opioid
6287Std. Mean Difference (IV, Random, 95% CI)-0.24 [-0.48, -7.12]

    9.2 Single-shot FNB + sciatic vs PCA opioid
292Std. Mean Difference (IV, Random, 95% CI)0.34 [-0.10, 0.78]

    9.3 Continuous FNB vs PCA opioid
7347Std. Mean Difference (IV, Random, 95% CI)-0.60 [-0.95, -0.24]

    9.4 Continuous FNB + sciatic vs PCA opioid
116Std. Mean Difference (IV, Random, 95% CI)-2.81 [-4.30, -1.32]

 10 Pain on movement 72 hours6438Std. Mean Difference (IV, Random, 95% CI)-0.17 [-0.39, 0.04]

    10.1 Single-shot FNB vs PCA opioid
4230Std. Mean Difference (IV, Random, 95% CI)-0.11 [-0.38, 0.16]

    10.2 Continuous FNB vs PCA opioid
3170Std. Mean Difference (IV, Random, 95% CI)-0.09 [-0.40, 0.23]

    10.3 Continuous FNB + sciatic vs PCA opioid
138Std. Mean Difference (IV, Random, 95% CI)-0.78 [-1.44, -0.12]

 11 Pain at rest 24 hours—subgrouped by FNB with and without concurrent PCA19Std. Mean Difference (Random, 95% CI)Subtotals only

    11.1 FNB with concurrent PCA
15Std. Mean Difference (Random, 95% CI)-0.67 [-0.94, -0.41]

    11.2 FNB without concurrent PCA
5Std. Mean Difference (Random, 95% CI)-0.93 [-1.31, -0.55]

 12 Pain on movement 24 hours—subgrouped by FNB with and without concurrent PCA17Std. Mean Difference (Random, 95% CI)Subtotals only

    12.1 Concurrent PCA in FNB
14Std. Mean Difference (Random, 95% CI)-0.67 [-0.99, -0.35]

    12.2 No concurrent PCA in FNB
4Std. Mean Difference (Random, 95% CI)-2.26 [-3.95, -0.57]

 13 Pain at rest 24 hours—subgrouped by FNB ropivacaine vs bupivacaine19Std. Mean Difference (Random, 95% CI)Subtotals only

    13.1 FNB with ropivacaine
8Std. Mean Difference (Random, 95% CI)-1.30 [-2.03, -0.58]

    13.2 FNB with bupivacaine
11Std. Mean Difference (Random, 95% CI)-0.61 [-0.89, -0.33]

 14 Pain on movement 24 hours—subgrouped by FNB ropivacaine vs bupivacaine17Std. Mean Difference (Random, 95% CI)Subtotals only

    14.1 FNB with ropivacaine
8Std. Mean Difference (Random, 95% CI)-0.98 [-1.67, -0.29]

    14.2 FNB with bupivacaine
10Std. Mean Difference (Random, 95% CI)-0.92 [-1.39, -0.44]

 15 Pain at rest 24 hours—sensitivity analysis by low bias for allocation concealment9Std. Mean Difference (Random, 95% CI)-0.54 [-0.76, -0.32]

 16 Pain on movement 24 hours—sensitivity analysis by low bias for allocation concealment9Std. Mean Difference (Random, 95% CI)-0.54 [-0.75, -0.33]

 17 Pain on rest 24 hours—sensitivity analysis by blinding of participants, personnel and outcome assessor7Std. Mean Difference (Random, 95% CI)-0.62 [-1.08, -0.17]

 18 Pain on movement 24 hours—sensitivity analysis by blinding of participants, personnel and outcome assessor7Std. Mean Difference (Random, 95% CI)-0.57 [-0.79, -0.35]

 19 Opioid consumption 24 hours (mg)20Mean Difference (Random, 95% CI)-14.74 [-18.68, -10.81]

    19.1 SFNB vs PCA opioid
12Mean Difference (Random, 95% CI)-12.86 [-18.65, -7.08]

    19.2 SFNB/Sciatic vs PCA opioid
2Mean Difference (Random, 95% CI)-17.93 [-21.43, -14.43]

    19.3 SFNB/Obturator vs PCA opioid
1Mean Difference (Random, 95% CI)-13.7 [-18.28, -9.12]

    19.4 CFNB vs PCA opioid
8Mean Difference (Random, 95% CI)-16.89 [-24.01, -9.77]

    19.5 CFNB/Sciatic vs PCA opioid
1Mean Difference (Random, 95% CI)-13.0 [-20.17, -5.83]

 20 Opioid consumption 48 hours (mg)191001Mean Difference (IV, Random, 95% CI)-14.53 [-20.03, -9.02]

    20.1 Single-shot FNB vs PCA opioid
11485Mean Difference (IV, Random, 95% CI)-13.21 [-21.99, -4.44]

    20.2 Single-shot FNB + sciatic vs PCA opioid
292Mean Difference (IV, Random, 95% CI)-10.10 [-18.26, -1.94]

    20.3 Continuous FNB vs PCA opioid
8386Mean Difference (IV, Random, 95% CI)-19.14 [-27.53, -10.76]

    20.4 Continuous FNB + sciatic vs PCA opioid
138Mean Difference (IV, Random, 95% CI)-6.0 [-17.39, 5.39]

 21 Nausea and/or vomiting161100Risk Ratio (M-H, Random, 95% CI)0.47 [0.33, 0.68]

    21.1 Single-shot FNB vs PCA opioid
8479Risk Ratio (M-H, Random, 95% CI)0.67 [0.44, 1.02]

    21.2 Single-shot FNB + obturator vs PCA opioid
147Risk Ratio (M-H, Random, 95% CI)0.25 [0.11, 0.56]

    21.3 Continuous FNB vs PCA opioid
9574Risk Ratio (M-H, Random, 95% CI)0.35 [0.18, 0.68]

 22 Sedation9808Risk Ratio (M-H, Random, 95% CI)0.34 [0.16, 0.74]

    22.1 Single-shot FNB vs PCA opioid
4326Risk Ratio (M-H, Random, 95% CI)0.52 [0.16, 1.75]

    22.2 Single-shot FNB + obturator vs PCA opioid
147Risk Ratio (M-H, Random, 95% CI)0.42 [0.15, 1.24]

    22.3 Continuous FNB vs PCA opioid
6435Risk Ratio (M-H, Random, 95% CI)0.20 [0.05, 0.77]

 23 Urinary retention7490Risk Ratio (M-H, Random, 95% CI)0.57 [0.20, 1.68]

    23.1 Single-shot FNB vs PCA opioid
3183Risk Ratio (M-H, Random, 95% CI)1.66 [0.43, 6.45]

    23.2 Continuous FNB vs PCA opioid
5307Risk Ratio (M-H, Random, 95% CI)0.29 [0.06, 1.36]

 24 Knee flexion range of motion (postoperative day 2 to 4)10541Mean Difference (IV, Random, 95% CI)6.48 [4.27, 8.69]

    24.1 Single-shot FNB vs PCA opioid
5295Mean Difference (IV, Random, 95% CI)3.74 [1.45, 6.04]

    24.2 Continuous FNB vs PCA opioid
4192Mean Difference (IV, Random, 95% CI)10.32 [4.70, 15.93]

    24.3 Continuous FNB + sciatic vs PCA opioid
254Mean Difference (IV, Random, 95% CI)12.78 [5.96, 19.60]

 25 Participant satisfaction with analgesia during hospital stay4180Mean Difference (IV, Random, 95% CI)1.68 [0.79, 2.58]

    25.1 Continuous FNB vs PCA opioid
4180Mean Difference (IV, Random, 95% CI)1.68 [0.79, 2.58]

 
Comparison 2. FNB versus epidural

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Pain at rest first 2 hours3Std. Mean Difference (Random, 95% CI)0.53 [-0.56, 1.62]

    1.1 Single-shot FNB vs epidural
1Std. Mean Difference (Random, 95% CI)2.08 [1.33, 2.83]

    1.2 Continuous FNB vs epidural
1Std. Mean Difference (Random, 95% CI)0.08 [-0.72, 0.88]

    1.3 Continuous FNB + sciatic vs epidural
2Std. Mean Difference (Random, 95% CI)-0.05 [-0.67, 0.57]

 2 Pain at rest 3 to 12 hours2120Std. Mean Difference (IV, Random, 95% CI)-0.20 [-1.08, 0.67]

    2.1 Continuous FNB vs epidural
170Std. Mean Difference (IV, Random, 95% CI)-0.64 [-1.12, -0.16]

    2.2 Continuous FNB + sciatic vs epidural
150Std. Mean Difference (IV, Random, 95% CI)0.25 [-0.30, 0.81]

 3 Pain at rest 24 hours6Std. Mean Difference (Random, 95% CI)-0.05 [-0.43, 0.32]

    3.1 Continuous FNB vs epidural
4Std. Mean Difference (Random, 95% CI)-0.11 [-0.72, 0.50]

    3.2 Continuous FNB + sciatic vs epidural
3Std. Mean Difference (Random, 95% CI)0.09 [-0.32, 0.51]

 4 Pain at rest 48 hours6328Std. Mean Difference (IV, Random, 95% CI)-0.14 [-0.51, 0.22]

    4.1 Continuous FNB vs epidural
4235Std. Mean Difference (IV, Random, 95% CI)-0.28 [-0.77, 0.21]

    4.2 Continuous FNB + sciatic vs epidural
393Std. Mean Difference (IV, Random, 95% CI)0.07 [-0.34, 0.49]

 5 Pain on movement 24 hours6317Std. Mean Difference (IV, Random, 95% CI)0.01 [-0.21, 0.24]

    5.1 Single-shot FNB + sciatic vs epidural
159Std. Mean Difference (IV, Random, 95% CI)-0.33 [-0.85, 0.18]

    5.2 Continuous FNB vs epidural
3165Std. Mean Difference (IV, Random, 95% CI)0.12 [-0.19, 0.43]

    5.3 Continuous FNB + sciatic vs epidural
393Std. Mean Difference (IV, Random, 95% CI)0.06 [-0.36, 0.47]

 6 Pain on movement 48 hours6317Std. Mean Difference (IV, Random, 95% CI)-0.10 [-0.32, 0.13]

    6.1 Single-shot FNB + sciatic vs epidural
159Std. Mean Difference (IV, Random, 95% CI)-0.41 [-0.92, 0.11]

    6.2 Continuous FNB vs epidural
3165Std. Mean Difference (IV, Random, 95% CI)-0.06 [-0.37, 0.25]

    6.3 Continuous FNB + sciatic vs epidural
393Std. Mean Difference (IV, Random, 95% CI)0.07 [-0.41, 0.54]

 7 Pain at rest 24 hours—subgrouped by FNB ropivacaine vs bupivacaine6Std. Mean Difference (Random, 95% CI)Subtotals only

    7.1 FNB with ropivacaine
4Std. Mean Difference (Random, 95% CI)-0.16 [-0.68, 0.37]

    7.2 FNB with bupivacaine
2Std. Mean Difference (Random, 95% CI)0.20 [-0.13, 0.53]

 8 Pain on movement 24 hours—subgrouped by FNB ropivacaine vs bupivacaine6Std. Mean Difference (IV, Random, 95% CI)Subtotals only

    8.1 FNB with ropivacaine
3120Std. Mean Difference (IV, Random, 95% CI)0.10 [-0.27, 0.47]

    8.2 FNB with bupivacaine
3197Std. Mean Difference (IV, Random, 95% CI)-0.03 [-0.31, 0.25]

 9 Pain at rest 24 hours—sensitivity analysis by low bias for allocation concealment3Std. Mean Difference (Random, 95% CI)0.20 [-0.07, 0.47]

 10 Pain on movement 24 hours—sensitivity analysis by low bias for allocation concealment4271Std. Mean Difference (IV, Random, 95% CI)0.03 [-0.21, 0.27]

 11 Opioid consumption 24 hours (mg)5341Mean Difference (IV, Random, 95% CI)-4.35 [-9.95, 1.26]

    11.1 Single-shot FNB + sciatic vs epidural
159Mean Difference (IV, Random, 95% CI)0.0 [-6.28, 6.28]

    11.2 Continuous FNB vs epidural
3205Mean Difference (IV, Random, 95% CI)-9.06 [-19.46, 1.34]

    11.3 Continuous FNB + sciatic vs epidural
277Mean Difference (IV, Random, 95% CI)-0.56 [-8.24, 7.12]

 12 Opioid consumption 48 hours (mg)4233Mean Difference (IV, Random, 95% CI)-1.28 [-5.30, 2.74]

    12.1 Single-shot FNB + sciatic vs epidural
159Mean Difference (IV, Random, 95% CI)-4.0 [-18.88, 10.88]

    12.2 Continuous FNB vs epidural
297Mean Difference (IV, Random, 95% CI)-3.54 [-12.42, 5.34]

    12.3 Continuous FNB + sciatic vs epidural
277Mean Difference (IV, Random, 95% CI)0.62 [-5.51, 6.75]

 13 Nausea and/or vomiting4183Risk Ratio (M-H, Random, 95% CI)0.63 [0.41, 0.97]

    13.1 Single-shot FNB vs epidural
142Risk Ratio (M-H, Random, 95% CI)0.64 [0.36, 1.15]

    13.2 Continuous FNB vs epidural
291Risk Ratio (M-H, Random, 95% CI)0.67 [0.22, 2.07]

    13.3 Continuous FNB + sciatic vs epidural
150Risk Ratio (M-H, Random, 95% CI)0.57 [0.10, 3.11]

 
Comparison 3. FNB versus local infiltration analgesia

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Pain at rest 24 hours4216Std. Mean Difference (IV, Random, 95% CI)0.06 [-0.61, 0.72]

    1.1 Single-shot FNB vs local infiltration
160Std. Mean Difference (IV, Random, 95% CI)0.50 [-0.01, 1.02]

    1.2 Continuous FNB vs local infiltration
3156Std. Mean Difference (IV, Random, 95% CI)-0.11 [-1.01, 0.80]

 2 Pain at rest 48 hours2Std. Mean Difference (IV, Random, 95% CI)Subtotals only

    2.1 Continuous FNB vs local infiltration
2114Std. Mean Difference (IV, Random, 95% CI)-0.26 [-0.94, 0.43]

 3 Pain on movement 24 hours3Std. Mean Difference (IV, Random, 95% CI)Subtotals only

    3.1 Continuous FNB vs local infiltration
3153Std. Mean Difference (IV, Random, 95% CI)0.38 [-0.10, 0.86]

 4 Pain on movement 48 hours2Std. Mean Difference (IV, Random, 95% CI)Subtotals only

    4.1 Continuous FNB vs local infiltration
2111Std. Mean Difference (IV, Random, 95% CI)-0.14 [-0.71, 0.43]

 5 Nausea and/or vomiting3177Risk Ratio (M-H, Random, 95% CI)1.71 [0.64, 4.62]

    5.1 SFNB vs local infiltration
160Risk Ratio (M-H, Random, 95% CI)2.14 [0.42, 10.80]

    5.2 CFNB vs local infiltration
2117Risk Ratio (M-H, Random, 95% CI)1.97 [0.35, 11.04]

 
Comparison 4. Continuous FNB versus single-shot FNB

Outcome or subgroup titleNo. of studiesNo. of participantsStatistical methodEffect size

 1 Pain at rest first 2 hours2156Std. Mean Difference (IV, Random, 95% CI)0.15 [-0.17, 0.46]

 2 Pain at rest 3 to 12 hours2156Std. Mean Difference (IV, Random, 95% CI)-0.03 [-0.35, 0.28]

 3 Pain at rest 24 hours4272Std. Mean Difference (IV, Random, 95% CI)-0.62 [-1.17, -0.07]

 4 Pain at rest 48 hours4272Std. Mean Difference (IV, Random, 95% CI)-0.96 [-1.69, -0.22]

 5 Pain on movement 24 hours4272Std. Mean Difference (IV, Random, 95% CI)-0.42 [-0.67, -0.17]

 6 Pain on movement 48 hours4272Std. Mean Difference (IV, Random, 95% CI)-0.54 [-1.02, -0.06]

 7 Pain on rest 24 hours—subgrouped by continuous FNB with or without concurrent PCA4Std. Mean Difference (IV, Random, 95% CI)Subtotals only

    7.1 Continuous FNB with concurrent PCA
3138Std. Mean Difference (IV, Random, 95% CI)-0.86 [-1.35, -0.38]

    7.2 Continuous FNB without concurrent PCA
1134Std. Mean Difference (IV, Random, 95% CI)-0.16 [-0.50, 0.18]

 8 Pain on movement 24 hours—subgrouped by continuous FNB with or without concurrent PCA4Std. Mean Difference (IV, Random, 95% CI)Subtotals only

    8.1 Continuous FNB with concurrent PCA
3138Std. Mean Difference (IV, Random, 95% CI)-0.59 [-0.96, -0.22]

    8.2 Continuous FNB without concurrent PCA
1134Std. Mean Difference (IV, Random, 95% CI)-0.27 [-0.61, 0.07]

 9 Pain at rest 24 hours—sensitivity analysis by low bias for allocation concealment3250Std. Mean Difference (IV, Random, 95% CI)-0.73 [-1.41, -0.04]

 10 Pain on movement 24 hours—sensitivity analysis by low bias for allocation concealment3250Std. Mean Difference (IV, Random, 95% CI)-0.47 [-0.79, -0.15]

 11 Opioid consumption 24 hours (mg)3236Mean Difference (IV, Random, 95% CI)-13.81 [-23.27, -4.35]

 12 Opioid consumption 48 hours (mg)4269Mean Difference (IV, Random, 95% CI)-14.59 [-22.35, -6.82]

 

Appendices

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
 

Appendix 1. Search strategy for CENTRAL, part of The Cochrane Library

#1 MeSH descriptor Arthroplasty, Replacement, Knee explode all trees
#2 MeSH descriptor Arthroplasty, Replacement explode all trees
#3 MeSH descriptor Arthroplasty explode all trees
#4 arthroplast* or (knee near (replacement or surg*))
#5 (#1 OR #2 OR #3 OR #4)
#6 MeSH descriptor Nerve Block explode all trees
#7 nerve block* or FNB or ((femoral or psoas or (lumbar plexus) or (fascia iliaca)) near block*)
#8 (#6 OR #7)
#9 (#5 AND #8)

 

Appendix 2. Search strategy for MEDLINE (Ovid SP)

1. exp Arthroplasty, Replacement, Knee/ or exp Arthroplasty, Replacement/ or exp Arthroplasty/ or arthroplast*.af. or (knee adj3 (replacement or surg*)).af.
2. nerve block*.af. or ((femoral or psoas or lumbar plexus or fascia iliaca) adj3 block*).mp. or FNB.mp. or exp Nerve block/
3. 1 and 2
4. ((randomized controlled trial or controlled clinical trial).pt. or randomized.ab. or placebo.ab. or drug therapy.fs. or randomly.ab. or trial.ab. or groups.ab.) not (animals not (humans and animals)).sh.
5. 3 and 4

 

Appendix 3. Search strategy for EMBASE (Ovid SP)

1. exp knee arthroplasty/ or exp arthroplasty/ or arthroplast*.af. or (knee adj3 (replacement or surg*)).mp.
2. nerve block*.af. or ((femoral or psoas or lumbar plexus or fascia iliaca) adj3 block).mp. or FNB.mp. or exp nerve block/
3. 1 and 2
4. (randomized-controlled-trial/ or randomization/ or controlled-study/ or multicenter-study/ or phase-3-clinical-trial/ or phase-4-clinical-trial/ or double-blind-procedure/ or single-blind-procedure/ or (random* or cross?over* or multicenter* or factorial* or placebo* or volunteer*).mp. or ((singl* or doubl* or trebl* or tripl*) adj3 (blind* or mask*)).ti,ab. or (latin adj square).mp.) not (animals not (humans and animals)).sh.
5. 3 and 4

 

Appendix 4. Search strategy for CINAHL (EBSCO host)

(((MH "Arthroplasty, Replacement, Knee+") OR (MH "Arthroplasty, Replacement") OR (MH "Arthroplasty") ) or arthroplast* or (knee and (replacement or surg*))) AND ((MM "Nerve Block") or (nerve block* or FNB) or ((femoral or psoas or (lumbar plexus) or (fascia iliaca)) and block*))

 

Appendix 5. Search strategy for Web of Science

#1 TS= arthroplast* or TS=(knee SAME (replacement or surg*))
#2 TS= (nerve block* or FNB) or TS=((femoral or psoas or (lumbar plexus) or (fascia iliaca)) SAMEblock*))
#3 (#1 and #2)
#4 TS=random* or TS=((clinical or controlled) SAME trial*)
#5 (#4 and #3)

 

Appendix 6. Study selection form


Title of article

Study ID (surname of first author and year published):


Report ID (if different from Study ID) (e.g. duplicate publications, follow-up studies)


Publication type (e.g. full report, abstract)


Study author contact details


Date form completed (dd/mm/yy)


Name of person extracting data



Eligibility criteria

Type of studyParticipantsInterventions            ComparisonsOutcomes

RCTTotal knee replacement surgery

 
FNB (single-shot or continuous) +/- sciatic/obturator block

 
  • PCA opioids
  • Epidural analgesia
  • Infiltration +/- intra-articular injection
  • Oral analgesia
  • Placebo
Circle:

Pain intensity, neurological injury, proportion of participants in pain postoperatively, time to first rescue analgesia, opioid consumption, supplemental postoperative analgesic requirements, knee range of motion, early mobilization, adverse effects, adverse events (postoperative falls, technical failures of block, reintervention), time to achieve discharge criteria and participant satisfaction with analgesia

Criterai met?

Yes/No/Unclear
Criteria met?

Yes/No/Unclear
Criteria met?

Yes/No/Unclear
Criteria met?

Yes/No/Unclear
Other outcome/s?

Include: Yes/No/Unclear

If unclear, comment:

Reason for exclusion:

Notes:



 

Appendix 7. Data extraction form


Study ID (surname of first author and year published)


Study characteristicsDescriptions (include comparative information for each intervention or comparison group if available)Further detailsSource (pg and/ fig/table/other)

Single centre/Multi-centre

Start and end dates of data collection

Duration of participation (from recruitment to last follow-up)

Power (e.g. power and sample size calculation, level of power achieved)

Notes:


Participant characteristics (record all reported measures)

Population description (from which study participants were drawn)

Setting (include location)

Inclusion criteria

Exclusion criteria

Method of recruitment (e.g. phone, mail, clinic patients)

Total no. randomly assigned

Baseline imbalances

Withdrawals and exclusions

Age

Sex

BMI

No. of participants in each groupIntervention 1:_____ ; Intervention 2:_____

Control 1: _____; Control 2: _____

No. of participants who received intended treatmentIntervention 1: _____ ; Intervention 2:_____

Control 1:_____; Control 2:______

No. of participants who were analysedIntervention 1: _____; Intervention 2:_____

Control 1:______; Control 2:______

Notes:


Interventions

Intervention group 1

FNB technique and type (i.e. continuous or single-shot FNB)

Additional blocks (i.e. sciatic or obturator) 

Description of FNB (include type of drug, dosage and regimen used)

Duration of treatment period

PCA opioid in FNB group?  Yes/No. If yes, describe

Type of co-analgesia/Supplemental analgesia

Loss to follow-up

Others


Intervention group 2

FNB technique and type (i.e. continuous or single-shot FNB)

Additional blocks (i.e. sciatic or obturator) 

Description of FNB (include type of drug, dosage and regimen used)

Duration of treatment period

PCA opioid in FNB group?  Yes/No. If yes, describe

Type of co-analgesia/Supplemental analgesia

Loss to follow-up

Others


Control group 1

Technique and type (i.e. PCA, epidural, infiltration +/- intra-articular injection, oral or placebo)

Drugs, dosage and regimen used

Placebo block in PCA group?  Yes/No. If yes, describe

Type of co-analgesia/Supplemental analgesia

Loss to follow-up

Others


Control group 2

Technique and type (i.e. PCA, epidural, infiltration +/- intra-articular injection, oral or placebo)

Drugs, dosage and regimen used

Placebo block in PCA group?  Yes/No. If yes, describe

Type of co-analgesia/Supplemental analgesia

Loss to follow-up

Others



*NA: not appropriate; NR: not required.


Outcomes Description (include outcome definition)Time points reported Person measuring/reportingImputation of missing dataFurther details

Pain intensity

(describe scale used, scale upper and lower limits and if high or low score is good, and whether scale is validated)

Proportion of participants in pain

Time to first rescue analgesia

Total opioid consumption

Adjunct oral analgesia

Knee range of motion

Early mobilization

Time to achieve discharge criteria

Adverse effects (nausea, vomiting, urinary retention, etc)

Technical failures of the block

Neurological injury

Mortality

Postoperative falls

Reintervention

Participant satisfaction with analgesia

(include scale used, scale upper and lower limits and if high or low score is good, and whether scale is validated)

Others:

Others:

Any outcomes collected but not reported? Yes/No

If yes, what outcome/s:

 




For continuous data (with a separate copy for each relevant intervention/control)

OutcomeUnit of measurement/Time pointIntervention groupControl groupNo. of missing participants in each group. Reasons missing?No. of participants moved from other group. Reasons moved?Details if outcome only described in text, or other summary statistics (SE, 95% CI)/If required statistics are not reportedSource (pg and/ fig/table/other)




nMean (SD)

(specify if other variance)
nMean (SD) (specify if other variance)

Pain intensity on movement (first 2 hours)

Pain intensity on movement (> 2 to 12 hours)      

Pain intensity on movement (> 12 to 24 hours)

Pain intensity on movement (> 24 to 72 hours)

Pain intensity on movement (> 72 hours)

Pain intensity at rest (first 2 hours)

Pain intensity at rest (> 2 to 12 hours)

Pain intensity at rest (> 12 to 24 hours)

Pain intensity at rest (> 24 to 72 hours)

Pain intensity at rest (> 72 hours)

Time to first rescue analgesia

Total opioid consumption      

Supplemental postoperative analgesic requirements

Knee range of motion      

Early mobilization

Time to achieve discharge criteria      

Participant satisfaction with analgesia      

Others




For dichotomous data (with a separate copy for each relevant intervention/control)

Outcomes

 
Intervention group (n/N)

where n = no. of participants with outcome, N = no. of participants randomly assigned
Control group (n/N)

where n = no. of participants with outcome, N = no. of participants randomly assigned
No. of missing participants in each group. Reasons missing?No. of participants moved from other group. Reasons moved?Location in text or source (pg and/ fig/table/other)

Proportion of participants in pain  

Nausea and/or vomiting  

Sedation  

Urinary retention  

Technical failure of blocks

Neurological injury

Mortality  

Postoperative falls

Reintervention

Others:




  


Other information relevant to the results                                                             

Indicate whether any data were obtained from the primary author and whether results were estimated from graphs etc or were calculated by you using a formula (the formula should be given). Provide information here if results not reported in the article are obtained.

 

 

 

Key conclusions of study authors:

Study funding sources:



 


Correspondence required for further study information (from whom, what and when)

 

 

 



 

References to other RCTs:


References to published reports of potentially eligible RCTs not already identified for this review? If yes, give details.

First authorJournal/ConferenceYear of publication

   

References to unpublished data from potentially eligible RCTs not already identified for this review? If yes, give details.

 



  

 

Appendix 8. Quality assessment of eligible trials form


DomainRisk of bias

(Low/High/Unclear)
Support for judgement

(Quotes/Comments)
Location in text or source (pg and/fig/table/ other)

Random sequence generation 

Allocation concealment  

Blinding of participants and personnel 

Blinding of outcome assessment  

Incomplete outcome data  addressed (short-term outcomes—during hospital admission) 

Incomplete outcome data  addressed (long-term outcomes—after discharge) 

Selective outcome reporting  

Intention-to-treat

Other bias

Notes:



Were withdrawals described? Yes/No/Unclear

Comment if any:

 

Appendix 9. Summary of findings


OutcomesIllustration comparative risks (95% CI)Relative effect

(95% CI)
No. of participants

(studies)
Quality of the evidence

(GRADE)
Comments

 

Assumed riskCorresponding risk

Pain at rest at 24 hours     

Pain on movement at 24 hours

Neurological injury

Total opioid consumption     

Nausea and/or vomiting

Knee range of motion

Participant satisfaction with analgesia     



 

 

Appendix 10. Fail-safe-N analysis


ComparisonOutcomeSubgroupEffect size (SMD)No. of studies (N)Fail-safe-n

1. FNB vs PCA opioid Analysis 1.1—Pain at rest at 24 hoursOverall-0.721960

1. FNB vs PCA opioid Analysis 1.2—Pain at rest at 24 hours by allocation concealmentLow risk of bias RCTs-0.54918

1. FNB vs PCA Opioid Analysis 1.5—Pain on movement at 24 hoursOverall-0.941778

1. FNB vs PCA opioid Analysis 1.6—Pain on movement at 24 hours by allocation concealmentLow risk of bias RCTs-0.54918

2. FNB vs epidural Analysis 2.1—Pain at Rrest at 24 hours< not significant, not applicable >



2. FNB vs epidural Analysis 2.5—Pain on movement at 24 hours< not significant, not applicable >



3. FNB vs local infiltration Analysis 2.1—Pain at rest at 24 hours< not significant, not applicable >



3. FNB vs local infiltration Analysis 2.5—Pain on movement at 24 hours< not significant, not applicable >



4. Continuous vs single-shot FNB Analysis 4.1—Pain at rest at 24 hoursOverall-0.6249

4. Continuous vs single-shot FNB Analysis 4.3—Pain on movement at 24 hoursOverall-0.4245



 

Contributions of authors

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review

Ee-Yuee Chan (EC), Marlene Fransen (MF), David A Parker (DA), Pryseley N Assam (PA), Nelson Chua (NC)

Conceiving of the review: EC

Co-ordinating the review: EC

Undertaking manual searches: EC

Screening search results: EC, MF

Organizing retrieval of papers: EC

Screening retrieved papers against inclusion criteria: EC, MF, NC

Appraising quality of papers: EC, MF

Abstracting data from papers: EC, MF, NC

Writing to authors of papers to ask for additional information: EC

Providing additional data about papers: EC

Obtaining and screening data on unpublished studies: EC, MF

Managing data for the review: EC

Entering data into Review Manager (RevMan 5.2): EC

Handling RevMan statistical data: EC, PA

Performing other statistical analysis not using RevMan: EC, PA

Interpreting data: EC, MF, PA, NC, DP

Making statistical inferences: EC, MF, PA, NC, DP

Writing the review: EC with support from the other review authors

Performing previous work that was the foundation of the present study: EC

Serving as guarantor for the review (one review author): EC

Taking responsibility for reading and checking the review before submission: EC

 

Declarations of interest

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review

Ee-Yuee Chan, Marlene Fransen and Nelson Chua were the study authors of an RCT (Chan 2013) that was eligible for inclusion in this Cochrane review.

Pryseley N Assam is a co-author of a possible publication arising from the RCT authored by Chan et al (Chan 2013).

David A Parker co-authored an RCT (Widmer 2012) that was also included in this review.

 

Sources of support

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review
 

Internal sources

  • Ee-Yuee Chan was supported by an International Postgraduate Research Scholarship, University of Sydney, Australia.

 

External sources

  • No sources of support supplied

 

Differences between protocol and review

  1. Top of page
  2. Summary of findings    [Explanations]
  3. Background
  4. Objectives
  5. Methods
  6. Results
  7. Discussion
  8. Authors' conclusions
  9. Acknowledgements
  10. Data and analyses
  11. Appendices
  12. Contributions of authors
  13. Declarations of interest
  14. Sources of support
  15. Differences between protocol and review

We made the following changes to the published protocol (Chan 2012).

1. Types of interventions.

We added a new comparison called continuous versus single-shot FNB for a more comprehensive review on FNB.

2. Primary outcomes: pain at rest and on movement.

We have reclassified pain at rest and on movement for the postoperative time frame ‘> 24 to 72’ to two categories: ’48 hours’ and ’72 hours.’  

3. Data synthesis.

For better clarity, our text in the ‘Data synthesis’ section was changed as follows.

The primary analyses include:

  • single-shot or continuous FNB ± sciatic/obturator block versus PCA opioid;

  • single-shot or continuous FNB ± sciatic/obturator block versus epidural analgesia;

  • single-shot or continuous FNB versus local infiltration analgesia;

  • single-shot or continuous FNB versus oral analgesia; and

  • continuous versus single-shot FNB.

 4. Unit of analysis issues.

A total of 20 RCTs were included with three intervention arms: multiple independent comparisons (e.g. FNB vs PCA and FNB vs epidural); multiple correlated comparisons with similar types of FNB (e.g. continuous FNB with ropivacaine vs PCA and continuous FNB with bupivacaine vs PCA) or multiple correlated comparisons with different types of FNB (e.g. single-shot FNB vs PCA and continuous FNB vs PCA). We have reworded our text in Unit of analysis issues to clarify.

5. Dealing with missing data.

Some of the included RCTs presented results using summary statistics other than mean (SD). In the review, we added details on how we handled these missing data.

 6. Subgroup analysis.

Because of limited data, subgroup analysis was restricted to:

  • type of FNB (single-shot or continuous FNB, with or without an additional sciatic/ obturator nerve block);
  • FNB with and without a concurrent parenteral opioid; and
  • type of FNB local anaesthetics (i.e. ropivacaine or bupivacaine).

 7. Sensitivity analysis.

Sensitivity analysis based on multiple interventions within studies was not performed because we followed the recommendations in the Cochrane Handbook for Systematic Reviews of Interventions (see Chapter 16; Higgins 2011), as discussed in the Unit of analysis issues section.

 8. SoF tables.

For the SoF tables, we have reduced the number of outcomes to seven: pain at rest at 24 hours, pain on movement at 24 hours, neurological injury, opioid consumption, nausea and vomiting, knee range of motion and participant satisfaction with analgesia, by excluding ‘time to first rescue analgesia’ and ‘early mobilisation’.  

 9. We changed the term ‘surgical infiltration with/without intra-articular injection’ to ‘local infiltration analgesia,’ as the latter appears to be commonly used in recent literature.

10. We defined ‘early ambulation’ as ‘time to first ambulation.’

* Indicates the major publication for the study

References

References to studies included in this review

  1. Top of page
  2. AbstractRésumé
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Differences between protocol and review
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. References to studies awaiting assessment
  21. Additional references
  22. References to other published versions of this review
Adams 2002 {published data only}
  • Adams HA, Saatweber P, Schmitz CS, Hecker H. Postoperative pain management in orthopaedic patients: no differences in pain score, but improved stress control by epidural anaesthesia. European Journal of Anaesthesiology 2002;19(9):658-65. [PUBMED: 12243289]
Affas 2011 {published data only}
  • Affas F, Nygrds EB, Stiller CO, Wretenberg P, Olofsson C. Pain control after total knee arthroplasty: a randomized trial comparing local infiltration anesthesia and continuous femoral block. Acta Orthopaedica 2011;82(4):441-7. [PUBMED: 21561303]
Allen 1998 {published data only}
  • Allen HW, Liu SS, Ware PD, Nairn CS, Owens BD. Peripheral nerve blocks improve analgesia after total knee replacement surgery. Anesthesia and Analgesia 1998;87(1):93-7. [PUBMED: 9661553 ]
Baranovic 2011 {published data only}
  • Baranovic S, Maldini B, Milosevic M, Golubic R, Nikolic T. Peripheral regional analgesia with femoral catheter versus intravenous patient controlled analgesia after total knee arthroplasty: a prospective randomized study. Collegium Antropologicum 2011;35(4):1209-14. [PUBMED: 22397261]
Barrington 2005 {published data only}
  • Barrington MJ, Olive D, Low K, Scott DA, Brittain J, Choong P. Continuous femoral nerve blockade or epidural analgesia after total knee replacement: a prospective randomized controlled trial. Anesthesia and Analgesia 2005;101(6):1824-9. [PUBMED: 16301267]
Carli 2010 {published data only}
  • Carli F, Clemente A, Asenjo JF, Kim DJ, Mistraletti G, Gomarasca M, et al. Analgesia and functional outcome after total knee arthroplasty: periarticular infiltration vs continuous femoral nerve block. British Journal of Anaesthesia 2010;105(2):185-95. [PUBMED: 20551021]
Chan 2012 {published data only}
  • Chan M-H, Chen W-H, Tung Y-W, Liu K, Tan P-H, Chia Y-Y. Single-injection femoral nerve block lacks preemptive effect on postoperative pain and morphine consumption in total knee arthroplasty. Acta Anaesthesiologica Taiwanica 2012;50:54-8. [PUBMED: 22769858]
Chan 2013 {published and unpublished data}
  • Chan EY, Fransen M, Sathappan S, Chua NH, Chan YH, Chua N. Comparing the analgesia effects of single-injection and continuous femoral nerve blocks with patient controlled analgesia after total knee arthroplasty. Journal of Arthroplasty 2013;28(4):608-13. [PUBMED: 23142441 ]
Davies 2004 {published data only}
  • Davies AF, Segar EP, Murdoch J, Wright DE, Wilson IH. Epidural infusion or combined femoral and sciatic nerve blocks as perioperative analgesia for knee arthroplasty. British Journal of Anaesthesia 2004;93(3):368-74. [PUBMED: 15247111]
de Lima e Souza 2008 {published and unpublished data}
  • de Lima e Souza R, Correa CH, Henriques MD, de Oliveira CB, Nunes TA, Gomez RS. Single-injection femoral nerve block with 0.25% ropivacaine or 0.25% bupivacaine for postoperative analgesia after total knee replacement or anterior cruciate ligament reconstruction. Journal of Clinical Anesthesia 2008;20(7):521-7. [PUBMED: 19019663]
Fritze 2009 {published data only}
  • Fritze P, Anderl S, Marouf A, Cumlivski R, Muller C, Pernicka E, et al. Pain therapy using stimulating catheters after total knee arthroplasty. Schmerz 2009;23(3):292-8. [PUBMED: 19308464]
Ganapathy 1999 {published data only}
  • Ganapathy S, Wasserman RA, Watson JT, Bennett J, Armstrong KP, Stockall CA, et al. Modified continuous femoral three-in-one block for postoperative pain after total knee arthroplasty. Anesthesia and Analgesia 1999;89(5):1197-202. [PUBMED: 10553834]
Good 2007 {published data only}
  • Good RP, Snedden MH, Schieber FC, Polachek A. Effects of a preoperative femoral nerve block on pain management and rehabilitation after total knee arthroplasty. American Journal of Orthopedics 2007;36(10):554-7. [PUBMED: 18033568]
Hirst 1996 {published data only}
  • Hirst GC, Lang SA, Dust WN, Cassidy JD, Yip RW. Femoral nerve block. Single injection versus continuous infusion for total knee arthroplasty. Regional Anesthesia 1996;21(4):292-7. [PUBMED: 8837185]
Hunt 2009 {published and unpublished data}
  • Hunt KJ, Bourne MH, Mariani EM. Single-injection femoral and sciatic nerve blocks for pain control after total knee arthroplasty. Journal of Arthroplasty 2009;24(4):533-8. [PUBMED: 19026519 ]
Kadic 2009 {published data only}
Kaloul 2004 {published data only}
  • Kaloul I, Guay J, Cote C, Fallaha M. The posterior lumbar plexus (psoas compartment) block and the three-in-one femoral nerve block provide similar postoperative analgesia after total knee replacement. Canadian Journal of Anaesthesia 2004;51(1):45-51. [PUBMED: 14709460]
Kardash 2007 {published and unpublished data}
  • Bergeron SG, Kardash KJ, Huk OL, Zukor DJ, Antoniou J. Functional outcome of femoral versus obturator nerve block after total knee arthroplasty. Clinical Orthopaedics & Related Research 2009;467(6):1458-62. [PUBMED: 19224305]
  • Kardash K, Hickey D, Tessler MJ, Payne S, Zukor D, Velly AM. Obturator versus femoral nerve block for analgesia after total knee arthroplasty. Anesthesia and Analgesia 2007;105(3):853-8. [PUBMED: 17717250]
Lee 2011 {published data only}
  • Lee AR, Choi DH, Ko JS, Choi SJ, Hahm TS, Kim GH, et al. Effect of combined single-injection femoral nerve block and patient-controlled epidural analgesia in patients undergoing total knee replacement. Yonsei Medical Journal 2011;52(1):145-50. [PUBMED: 21155047 ]
Long 2006 {published data only}
  • Long WT, Ward SR, Dorr LD, Raya J, Boutary M, Sirianni LE. Postoperative pain management following total knee arthroplasty: a randomized comparison of continuous epidural versus femoral nerve infusion. The Journal of Knee Surgery 2006;19(2):137-43. [PUBMED: 16642893]
Macalou 2004 {published data only}
  • Macalou D, Trueck S, Meuret P, Heck M, Vial F, Ouologuem S, et al. Postoperative analgesia after total knee replacement: the effect of an obturator nerve block added to the femoral 3-in-1 nerve block. Anesthesia and Analgesia 2004;99(1):251-4. [PUBMED: 15281539]
Martin 2008 {published data only}
  • Martin F, Martinez V, Mazoit JX, Bouhassira D, Cherif K, Gentili ME, et al. Antiinflammatory effect of peripheral nerve blocks after knee surgery: clinical and biologic evaluation. Anesthesiology 2008;109(3):484-90. [PUBMED: 18719447]
McNamee 2001 {published data only}
Mistraletti 2006 {published data only}
  • Mistraletti G, De La Cuadra-Fontaine JC, Asenjo FJ, Donatelli F, Wykes L, Schricker T, et al. Comparison of analgesic methods for total knee arthroplasty: metabolic effect of exogenous glucose. Regional Anesthesia & Pain Medicine 2006;31(3):260-9. [PUBMED: 16701193]
Nader 2012 {published data only}
Ng 2001 {published data only}
  • Ng HP, Cheong KF, Lim A, Lim J, Puhaindran ME. Intraoperative single-shot "3-in-1" femoral nerve block with ropivacaine 0.25%, ropivacaine 0.5% or bupivacaine 0.25% provides comparable 48-hr analgesia after unilateral total knee replacement. Canadian Journal of Anaesthesia 2001;48(11):1102-8. [PUBMED: 11744586]
Ng 2012 {published data only}
  • Ng FY, Ng JKF, Chiu KY, Yan CH, Chan CW. Multimodal periarticular injection vs continuous femoral nerve block after total knee arthroplasty. A prospective, crossover, randomized clinical trial. Journal of Arthroplasty 2012;27(6):1234-8. [PUBMED: 22325963 ]
Ozen 2006 {published data only}
  • Ozen M, Inan N, Tumer F, Uyar A, Baltaci B. The effect of 3-in-1 femoral nerve block with ropivacaine 0.375% on postoperative morphine consumption in elderly patients after total knee replacement surgery. Agri Dergisi 2006;18(4):44-50. [PUBMED: 17457713]
Park 2010 {published data only}
  • Park CK, Cho CK, Lee GG, Lee JH. Optimizing dose infusion of 0.125% bupivacaine for continuous femoral nerve block after total knee replacement. Korean Journal of Anesthesiology 2010;58(5):468-76. [PUBMED: 20532056 ]
Parvataneni 2007 {published data only}
  • Parvataneni HK, Shah VP, Howard H, Cole N, Ranawat AS, Ranawat CS. Controlling pain after total hip and knee arthroplasty using a multimodal protocol with local periarticular injections: a prospective randomized study. Journal of Arthroplasty 2007;22(6):33-8. [PUBMED: 17823012]
Salinas 2006 {published data only}
  • Salinas FV, Liu SS, Mulroy MF. The effect of single-injection femoral nerve block versus continuous femoral nerve block after total knee arthroplasty on hospital length of stay and long-term functional recovery within an established clinical pathway. Anesthesia and Analgesia 2006;102(4):1234-9. [PUBMED: 16551930]
Seet 2006 {published and unpublished data}
  • Seet E, Leong WL, Yeo ASN, Fook-Chong S. Effectiveness of 3-in-1 continuous femoral block of differing concentrations compared to patient controlled intravenous morphine for post total knee arthroplasty analgesia and knee rehabilitation. Anaesthesia and Intensive Care 2006;34(1):25-30. [PUBMED: 16494145 ]
  • Shum CF, Lo NN, Yeo SJ, Yang KY, Chong HC, Yeo SN. Continuous femoral nerve block in total knee arthroplasty: immediate and two-year outcomes. Journal of Arthroplasty 2009;24(2):204-9. [PUBMED: 18534496]
Serpell 2001 {published data only}
Singelyn 1998 {published data only}
  • Singelyn FJ, Deyaert M, Joris D, Pendeville E, Gouverneur JM. Effects of intravenous patient-controlled analgesia with morphine, continuous epidural analgesia, and continuous three-in-one block on postoperative pain and knee rehabilitation after unilateral total knee arthroplasty. Anesthesia and Analgesia 1998;87(1):88-92. [PUBMED: 9661552]
Sundarathiti 2009 {published data only}
  • Sundarathiti P, Ruananukul N, Channum T, Kitkunasathean C, Mantay A, Thammasakulsiri J, et al. A comparison of continuous femoral nerve block (CFNB) and continuous epidural infusion (CEI) in postoperative analgesia and knee rehabilitation after total knee arthroplasty (TKA). Journal of the Medical Association of Thailand 2009;92(3):328-34. [PUBMED: 19301724 ]
Szczukowski 2004 {published data only}
  • Szczukowski MJ Jr, Hines JA, Snell JA, Sisca TS. Femoral nerve block for total knee arthroplasty patients: a method to control postoperative pain. Journal of Arthroplasty 2004;19(6):720-5. [PUBMED: 15343531]
Tang 2010 {published and unpublished data}
  • Tang S, Xu ZH, Huang YG, He K, Ren LY, Qian WW, et al. Comparison of the influences of continuous femoral nerve block and patient controlled intravenous analgesia on total knee arthroplasty. [Chinese]. Acta Academiae Medicinae Sinicae 2010;32(5):574-8. [PUBMED: 21050565]
Toftdahl 2007 {published and unpublished data}
  • Toftdahl K, Nikolajsen L, Haraldsted V, Madsen F, Tonnesen EK, Soballe K. Comparison of peri- and intraarticular analgesia with femoral nerve block after total knee arthroplasty: a randomized clinical trial. Acta Orthopaedica 2007;78(2):172-9. [PUBMED: 17464603 ]
Tugay 2006 {published and unpublished data}
  • Tugay N, Saricaoglu F, Satilmis T, Alpar U, Akarcali I, Citaker S, et al. Single-injection femoral nerve block. Effects on the independence level in functional activities in the early postoperative period in patients with total knee arthroplasty. Neurosciences 2006;11(3):175-9. [PUBMED: 22266616 ]
Wang 2002 {published data only}
  • Wang H, Boctor B, Verner J. The effect of single-injection femoral nerve block on rehabilitation and length of hospital stay after total knee replacement. Regional Anesthesia and Pain Medicine 2002;27(2):139-44. [PUBMED: 11915059 ]
Wang 2010 {published data only}
  • Wang H-J, Zhang D-Z, Li S-Z. Comparing the analgesic efficacy of continuous femoral nerve blockade and continuous intravenous analgesia after total knee arthroplasty. [Chinese]. Chung Hua I Hsueh Tsa Chih [Chinese Medical Journal] 2010;90(33):2360-2. [PUBMED: 21092500]
Widmer 2012 {published data only}
  • Widmer BJ, Scholes CJ, Pattullo GG, Oussedik SI, Parker DA, Coolican MRJ. Is femoral nerve block necessary during total knee arthroplasty? A randomized controlled trial. Journal of Arthroplasty 2012;27:1800-5. [PUBMED: 22658231]
Xie 2012 {published data only}
  • Xie Z, Hussain W, Cutter TW, Apfelbaum JL, Drum ML, Manning DW. Three-in-one nerve block with different concentrations of bupivacaine in total knee arthroplasty. Randomized, placebo-controlled, double-blind trial. Journal of Arthroplasty 2012;27(5):673-8.e1. [PUBMED: 21945081]
Yu 2010 {published data only}
  • Yu H-P, Liu Z-H, Guo W-S, Jiang H-Y, Zhao J. Effect of continuous femoral nerve block in analgesia and the early rehabilitation after total knee replacement. [Chinese]. Zhongguo Gushang [China Journal of Orthopaedics and Traumatology] 2010;23(11):825-7. [PUBMED: 21254673]
Zaric 2006 {published and unpublished data}
  • Zaric D, Boysen K, Christiansen C, Christiansen J, Stephensen S, Christensen B. A comparison of epidural analgesia with combined continuous femoral-sciatic nerve blocks after total knee replacement. Anesthesia and Analgesia 2006;102(4):1240-6. [PUBMED: 16551931]

References to studies excluded from this review

  1. Top of page
  2. AbstractRésumé
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Differences between protocol and review
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. References to studies awaiting assessment
  21. Additional references
  22. References to other published versions of this review
Affas 2012 {published data only}
  • Affas F, Stiller CO, Nygards EB, Stephanson N, Wretenberg P, Olofsson C. A randomized study comparing plasma concentration of ropivacaine after local infiltration analgesia and femoral block in primary total knee arthroplasty. Scandinavian Journal of Pain 2012;3(1):46-51. [DOI: 10.1016/j.sjpain.2011.09.001]
Bagry 2008 {published data only}
  • Bagry H, de la Cuadra Fontaine JC, Asenjo JF, Bracco D, Carli F. Effect of a continuous peripheral nerve block on the inflammatory response in knee arthroplasty. Regional Anesthesia and Pain Medicine 2008;33(1):17-23. [PUBMED: 18155052]
Blisard 2012 {published data only}
  • Blisard R, Haddad FS. Pre-emptive peripheral nerve block delays recovery after total knee arthroplasty. Orthopedics Today 2012; Vol. 32, issue 2:31-2.
Cappelleri 2011 {published data only}
  • Cappelleri G, Ghisi D, Fanelli A, Albertin A, Somalvico F, Aldegheri G. Does continuous sciatic nerve block improve postoperative analgesia and early rehabilitation after total knee arthroplasty? A prospective, randomized, double-blinded study. Regional Anesthesia and Pain Medicine 2011;36(5):489-92. [PUBMED: 21857276]
Carvalho 2012 {published data only}
  • Carvalho R, Braganca JP, Calixto L. Effect of a single shot sciatic nerve block combined with a continuous femoral block on pain scores after knee arthroplasty. A randomized controlled trial. British Journal of Anaesthesia 2012;108:23-4. [DOI: 10.4236/ojanes.2012.24025]
Chelly 2001 {published data only}
  • Chelly JE, Greger J, Gebhard R, Coupe K, Clyburn TA, Buckle R, et al. Continuous femoral blocks improve recovery and outcome of patients undergoing total knee arthroplasty. Journal of Arthroplasty 2001;16(4):436-45. [PUBMED: 11402405]]
Combes 2000 {published data only}
  • Combes X, Cerf C, Bouleau D, Duvaldestin P, Dhonneur G. The effects of residual pain on oxygenation and breathing pattern during morphine analgesia. Anesthesia and Analgesia 2000;90(1):156-60. [PUBMED: 10624997]
Dang 2005 {published data only}
  • Pham Dang C, Gautheron E, Guilley J, Fernandez M, Waast D, Volteau C, et al. The value of adding sciatic block to continuous femoral block for analgesia after total knee replacement. Regional Anesthesia and Pain Medicine 2005;30(2):128-33. [PUBMED: 15765454]
Edwards 1992 {published data only}
  • Edwards ND, Wright EM. Continuous low-dose 3-in-1 nerve blockade for postoperative pain relief after total knee replacement. Anesthesia and Analgesia 1992;75(2):265-7. [PUBMED: 1632541]
Frassanito 2009 {published data only}
  • Frassanito L, Vergari A, Messina A, Pitoni S, Puglisi C, Chierichini A. Anaesthesia for total knee arthroplasty: efficacy of single-injection or continuous lumbar plexus associated with sciatic nerve blocks—a randomized controlled study. European Review for Medical and Pharmacological Sciences 2009;13(5):375-82. [MEDLINE: 19961044]
Frassanito 2010 {published data only}
  • Frassanito L, Vergari A, Zanghi F, Messina A, Bitondo M, Antonelli M. Post-operative analgesia following total knee arthroplasty: comparison of low-dose intrathecal morphine and single-shot ultrasound-guided femoral nerve block: a randomized, single blinded, controlled study. European Review for Medical & Pharmacological Sciences 2010;14(7):589-96. [PUBMED: 20707248]
Hakkalamani 2008 {published data only}
  • Hakkalamani S, Carroll FA, Ford C, Mereddy P, Jefferies G, Parkinson RW. Analgesia in total knee replacement: a comparison between femoral versus combined femoral and sciatic nerve block. Journal of Bone and Joint Surgery (Proceedings) 2008;90b (supp):328-E0A.
Ilfeld 2008 {published data only}
  • Ilfeld BM, Le LT, Meyer RS, Mariano ER, Vandenborne K, Duncan PW, et al. Ambulatory continuous femoral nerve blocks decrease time to discharge readiness after tricompartment total knee arthroplasty: a randomized, triple-masked, placebo-controlled study. Anesthesiology 2008;108(4):703-13. [PUBMED: 18362603]
Ilfeld 2009 {published data only}
  • Ilfeld BM, Meyer RS, Le LT, Mariano ER, Williams BA, Vandenborne K, et al. Health-related quality of life after tricompartment knee arthroplasty with and without an extended-duration continuous femoral nerve block: a prospective, 1-year follow-up of a randomized, triple-masked, placebo-controlled study. Anesthesia and Analgesia 2009;108(4):1320-5. [PUBMED: 19299806]
Ilfeld 2010 {published data only}
  • Ilfeld BM, Mariano ER, Girard PJ, Loland VJ, Meyer RS, Donovan JF, et al. A multicenter, randomized, triple-masked, placebo-controlled trial of the effect of ambulatory continuous femoral nerve blocks on discharge-readiness following total knee arthroplasty in patients on general orthopaedic wards. Pain 2010;150(3):477-84. [PUBMED: 20573448]
Johnson 2011 {published data only}
  • Johnson CB, Steele-Moses SK. The use of continuous femoral nerve blocks versus extended release epidural morphine: a study comparing outcomes in total knee arthroplasty procedures. Orthopedic Nursing 2011;30(1):44-53. [MEDLINE: 21278555]
Koh 2011 {published data only}
  • Koh IJ, Kang YG, Chang CB, Do SH, Seong SC, Kim TK. Does periarticular injection have additional pain relieving effects during contemporary multimodal pain control protocols for TKA? A randomised, controlled study. Knee 2012;19(4):253-9. [PUBMED: 21507661]
McMeniman 2010 {published data only}
  • McMeniman TJ, McMeniman PJ, Myers PT, Hayes DA, Cavdarski A, Wong M, et al. Femoral nerve block vs fascia iliaca block for total knee arthroplasty postoperative pain control: a prospective, randomized controlled trial. Journal of Arthroplasty 2010;25(8):1246-9. [PUBMED: 20178889]
Meftah 2012 {published data only}
  • Meftah M, Wong AC, Nawabi DH, Yun RJ, Ranawat AS, Ranawat CS. Pain management after total knee arthroplasty using a multimodal approach. Orthopedics 2012;35(5):e660-4. [PUBMED: 22588407]
Morin 2005 {published data only}
  • Morin AM, Kratz CD, Eberhart LHJ, Dinges G, Heider E, Schwarz N, et al. Postoperative analgesia and functional recovery after total-knee replacement: comparison of a continuous posterior lumbar plexus (psoas compartment) block, a continuous femoral nerve block, and the combination of a continuous femoral and sciatic nerve block. Regional Anesthesia and Pain Medicine 2005;30(5):434-45. [PUBMED: 16135347]
Ng 2012b {published data only}
  • Ng F-Y, Chiu K-Y, Yan CH, Ng K-FJ. Continuous femoral nerve block versus patient-controlled analgesia following total knee arthroplasty. Journal of Orthopaedic Surgery 2012;20:23-6. [PUBMED: 22535806]
Niskanen 2005 {published data only}
  • Niskanen RO, Strandberg N. Bedside femoral block performed on the first postoperative day after unilateral total knee arthroplasty: a randomized study of 49 patients. The Journal of Knee Surgery 2005;18(3):192-6. [PUBMED: 16152867]
Rais 2009 {published data only}
  • Rais K, Ben Said A, Soussi M, Chahed S, Kaabachi O. Multimodal regional and systemic approach for postoperative analgesia in total knee arthroplasty. European Journal of Anaesthesiology 2009;26:123.
Rajeev 2007 {published data only}
  • Rajeev S, Batra YK, Panda NB, Kumar M, Nagi ON. Combined continuous "3-in-1" and sciatic nerve blocks provide improved postoperative analgesia with no correlation to catheter tip location after unilateral total knee arthroplasty. Journal of Arthroplasty 2007;22(8):1181-6. [PUBMED: 18078888]
Rasiah 2012 {published data only}
  • Rasiah R, Azhar AA, Thevanthiran MN. Single injection of femoral nerve block for bilateral total knee arthroplasty for post-operative pain management. British Journal of Anaesthesia 2012;108:ii411.
Safa 2011 {published data only}
  • Safa B, Haslam L, Gollish J, McCartney C. A prospective, randomized trial, comparing analgesic efficacy and postoperative functional recovery of either single shot sciatic nerve block or posterior capsule infiltration combined with femoral block for total knee arthroplasty. Regional Anesthesia and Pain Medicine 2011;36:508.
Serrano 2011 {published data only}
  • Serrano A, Santiveri X, Bisbe E, Ortiz P, Puig L, Castillo J. Analgesic efficacy of associating a sciatic block to a femoral block in the postoperative period of total knee arthroplasty. European Journal of Anaesthesiology 2011;28:119-20.
Sites 2004 {published data only}
  • Sites BD, Beach M, Gallagher JD, Jarrett RA, Sparks MB, Lundberg CJF. A single injection ultrasound-assisted femoral nerve block provides side effect-sparing analgesia when compared with intrathecal morphine in patients undergoing total knee arthroplasty. Anesthesia and Analgesia 2004;99(5):1539-43; table of contents. [PUBMED: 15502061]
Taninishi 2011 {published data only}
  • Taninishi H, Sato K, Morita K. Effects of anterior sciatic nerve block on intraoperative hemodynamics and pain relief in the postanesthesia care unit for patients undergoing total knee arthroplasty. Regional Anesthesia and Pain Medicine 2011;36(5):E263.
Tarkkila 1998 {published data only}
  • Tarkkila P, Tuominen M, Huhtala J, Lindgren L. Comparison of intrathecal morphine and continuous femoral 3-in-1 block for pain after major knee surgery under spinal anaesthesia. European Journal of Anaesthesiology 1998;15(1):6-9. [PUBMED: 9522133]
Tricarico 2009 {published data only}
  • Tricarico E, Tomasino S, D'Orlando L. Epidural analgesia compared with peripheral nerve blockade after major knee surgery. Critical Care 2009;13:S160.
Watson 2005 {published data only}
  • Watson MW, Mitra D, McLintock TC, Grant SA. Continuous versus single-injection lumbar plexus blocks: comparison of the effects on morphine use and early recovery after total knee arthroplasty. Regional Anesthesia & Pain Medicine 2005;30(6):541-7. [PUBMED: 16326339]
Wegener 2011 {published data only}
  • Wegener JT, van Ooij B, van Dijk CN, Hollmann MW, Preckel B, Stevens MF. Value of single-injection or continuous sciatic nerve block in addition to a continuous femoral nerve block in patients undergoing total knee arthroplasty: a prospective, randomized, controlled trial. Regional Anesthesia & Pain Medicine 2011;36(5):481-8. [PUBMED: 21857273]
Weston-Simons 2012 {published data only}
  • Weston-Simons JS, Pandit H, Haliker V, Dodd CA, Popat MT, Murray DW. Intra-articular local anaesthetic on the day after surgery improves pain and patient satisfaction after unicompartmental knee replacement: a randomised controlled trial. Knee 2012;19:352-5. [PUBMED: 21669534]
Zhang 2010 {published data only}
  • Zhang HH, Yan SH, Li X, Jin Y, Liu ZC. Analgesia following artificial joint replacement joint replacement: nerve block based on gait analysis. Journal of Clinical Rehabilitative Tissue Engineering Research 2010;14(22):4018-22.
Ziwenga 2010 {published data only}
  • Ziwenga O, Tsui B, Sriramatr D. Comparison of quadriceps weakness following total knee arthroplasty using analgesia by femoral nerve block: continuous vs patient controlled techniques. Regional Anesthesia and Pain Medicine 2010;35(5):E194.

References to studies awaiting assessment

  1. Top of page
  2. AbstractRésumé
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Differences between protocol and review
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. References to studies awaiting assessment
  21. Additional references
  22. References to other published versions of this review
Grider 2011 {published data only}
  • Grider JS, Harned ME, Paul S, Mauro G. Comparison of single shot versus continuous femoral local anesthetic nerve block in patients undergoing knee arthroplasty. Regional Anesthesia and Pain Medicine 2011;36(5):508-20.
Mullen 2008 {published data only}
  • Mullen M, Rooney BP, Kelly MP, Storey N. 24 hour infusion femoral and sciatic nerve block following total knee arthroplasty. Scottish Medical Journal 2008;2:59.
Tobin 2011 {published data only}
  • Tobin R, Singh MK, Sharma P, Girotra G, Arora D, Panigrahi B. Ultrasound guided in-plane continuous femoral nerve block for postoperative analgesia & early mobilisation in patients undergoing unilateral total knee arthroplasty—an Indian experience. Regional Anesthesia and Pain Medicine 2011;36(5):E263.
Yuksel 2011 {published data only}
  • Yuksel BE, Doger C, Erdogan N, Ornek D, Kadiogullari N. Continuous epidural analgesia versus combination of single dose sciatic nerve block and continuous femoral analgesia in total knee arthroplasty. Regional Anesthesia and Pain Medicine 2011;36(5):E183-E4.

Additional references

  1. Top of page
  2. AbstractRésumé
  3. Summary of findings
  4. Background
  5. Objectives
  6. Methods
  7. Results
  8. Discussion
  9. Authors' conclusions
  10. Acknowledgements
  11. Data and analyses
  12. Appendices
  13. Contributions of authors
  14. Declarations of interest
  15. Sources of support
  16. Differences between protocol and review
  17. Characteristics of studies
  18. References to studies included in this review
  19. References to studies excluded from this review
  20. References to studies awaiting assessment
  21. Additional references
  22. References to other published versions of this review
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