Proximal femoral fractures or, as they are more generally termed, 'hip fractures', can be subdivided into intracapsular fractures (those occurring proximal to the attachment of the hip joint capsule to the femur) and extracapsular (those occurring distal to the hip joint capsule). Intracapsular fractures can be further subdivided into those which are displaced and those which are essentially undisplaced. Undisplaced fractures include those termed impacted or adduction fractures. Many other subdivisions and classification methods exist for intracapsular fractures but these have not been shown to be of reliable clinical usefulness (Parker 1993).
Intracapsular hip fractures are generally managed surgically, either by fixing the fracture using various implants and thereby retaining the femoral head, or by replacing the femoral head with a prosthesis. The latter option is not considered in this review. The rationale for operative treatment of intracapsular fractures is to reduce the risk of the fracture displacing, for undisplaced fractures, and to maintain fracture reduction for displaced fractures. Surgery entails passing single or multiple screws or pins across the fracture site. For displaced fractures the fracture must first be reduced, which may be achieved either by an open or closed reduction.
Numerous implants have been developed over time for the internal fixation of the fracture. Tronzo identified over 100 in 1974 (Tronzo 1974). These implants are inserted under X-ray guidance using either an open or percutaneous procedure. Implants may be divided into those which are smooth (pins) and those which are threaded (screws). The type of threads used on screws may vary from narrow to wide and deep. In addition, the proportion of the screw which is threaded may vary from the tip only to the entire length. The number of pins or screws inserted across the fracture can vary from one to in excess of 10, depending on the size of the implant used. Screws or pins may also be connected to a side plate which is then fixed with screws to the side of the femur. Another variation on implant design is a small metal 'tongue' which is pushed out of the tip of a nail into the subchondral bone of the femur.
Examples of single nails are the Smith-Petersen nail, Thornton nail and Rydell four-flanged nail. Examples of a single nail with a side plate are the Holt, Jewett nail plate, Massie nail, McLaughlin nail plate, Pugh nail and Thornton nail plate. Of these implants, the Massie and Pugh nails have the capacity for sliding at the nail/plate junction, allowing for collapse at the fracture site. Examples of a single screw with a side plate are the sliding hip screw (SHS) and equivalent models such as the Ambi, Dynamic, or Richards' screws. These implants all have the capacity for sliding at the screw/plate junction.
Examples of implants with a 'tongue', which can be extruded from its tip, are the Rydell four-flanged nail and Hansson pins. Examples of implants that are normally used in pairs are Garden screws, Hansson pins, Richards' screws, Tronzo (VLF) screws, Uppsala/Olmed screws, von Bahr screws, and Ullevaal screws. Examples of implants for which three are normally inserted are AO screws, Gouffon screws, Hessel pins, Mecron screws, Nystrom nails, Ullevaal screws and Scand screws.
The main fracture healing complication after internal fixation of an intracapsular fracture is the failure of the fracture to heal. This may lead to fracture displacement and is termed either 'early fracture displacement' or 'non-union' if it occurs in the first few weeks after operation. The term 'non-union' is also used for those fractures which fail to heal in later weeks. This normally results in the fracture displacing with loss of position of the fixation device. For this review the term non-union refers to both those fractures which show early displacement plus those which later fail to heal. An incidence of non-union of five to ten per cent can be expected following an undisplaced intracapsular fracture; this rises to about 20 to 40 per cent for displaced intracapsular fractures (Lu-Yao 1994; Parker 1993).
The other main fracture healing complication is avascular necrosis (also termed segmental collapse or femoral head necrosis). This is seen as collapse of the femoral head and subsequent destruction of the hip joint. It occurs secondary to disruption of the blood supply to the femoral head. An incidence of 16 per cent for displaced intracapsular fractures has been reported (Lu-Yao 1994).
Other fracture healing complications that may occur are backing out of the implant as the fracture collapses, fracture below or around the implant and breakage of the implant.
To identify and summarise the evidence from randomised controlled trials of the effects of different implants for the internal fixation of intracapsular proximal femoral fractures.
Criteria for considering studies for this review
Types of studies
All randomised controlled trials comparing alternative implants. Quasi-randomised trials (for example, allocation by alternation or date of birth) and trials in which the treatment allocation was inadequately concealed were considered for inclusion. No language restriction was applied.
Types of participants
Skeletally mature patients with an intracapsular proximal femoral fracture.
Types of interventions
Implants used for internal fixation of an intracapsular proximal femoral fracture.
Types of outcome measures
The principal outcome measure was the non-union rate which includes early displacement of the fracture. Data for the following outcomes were sought:
a) Operative details
- length of surgery (in minutes)
- operative blood loss (in millilitres)
- number of patients transfused
- post-operative blood transfusion (in units)
- radiographic screening time (in seconds)
b) Fracture fixation complications
- non-union of the fracture within the follow-up period (the definition of non-union will be that used within each individual study and this outcome will include early re-displacement of the fracture).
- avascular necrosis
- fracture below the implant
- other surgical complications of fixation (as detailed in each study)
- total fracture fixation complications (sum of the four above outcomes)
- re-operation (within the follow-up period of the study).
- superficial wound infection (infection of the wound in which there is no evidence that the infection extends beneath the deep fascia to the site of the implant)
- deep wound infection (infection around the implant)
- wound haematoma
c) Post-operative complications
- thromboembolic complications (deep vein thrombosis or pulmonary embolism)
- any medical complications (as detailed in each individual study)
- length of hospital stay (in days)
d) Anatomical restoration
- shortening (as defined in each study)
- varus deformity (as defined in each study)
- external rotation deformity (> 20 degrees)
e) Final outcome measures
- mortality (within the follow-up period of the study)
- pain (persistent pain at the final follow-up assessment)
- residence at final follow-up (return to living at home, discharge location)
- mobility (use of walking aids, return of mobility)
- regain of activities of daily living
- health related quality of life measures
Search methods for identification of studies
We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (13 September 2010), the Cochrane Central Register of Controlled Trials (2010, Issue 3), MEDLINE (1950 to August week 5 2010) and EMBASE (1980 to 2010 Week 36). We searched the WHO International Clinical Trials Registry Platform Search Portal, Current Controlled Trials, and the UK National Research Register (NRR) Archive (all to April 2009) to identify ongoing and recently completed trials. No language or publication restrictions were applied.
The generic search strategies for hip fracture trials run in The Cochrane Library (Wiley Online Library) and MEDLINE (2002 onwards) are shown in Appendix 1. This MEDLINE search was combined with the sensitivity- and precision-maximizing version of the Cochrane Highly Sensitive Search Strategy for identifying randomized trials (Lefebvre 2009). The general search strategy for hip fracture trials in EMBASE (2002 onwards) is also shown in Appendix 1.
Searching other resources
We searched reference lists of articles and our own reference databases. We included the findings from handsearches of the British Volume of the Journal of Bone and Joint Surgery supplements (1996 to 2006), abstracts of the American Orthopaedic Trauma Association annual meetings (1996 to 2006) and American Academy of Orthopaedic Surgeons annual meetings (2004 to 2007). We also included handsearch results from the final programmes of SICOT (1996 and 1999) and SICOT/SIROT (2003), EFORT (2007) and the British Orthopaedic Association Congress (2000, 2001, 2002, 2003, 2005 and 2006). Up to 2007, we scrutinised weekly downloads of "Fracture" articles in new issues of Acta Orthopaedica Scandinavica (subsequently Acta Orthopaedica); American Journal of Orthopedics; Archives of Orthopaedic and Trauma Surgery; Clinical Orthopedics and Related Research; Injury; Journal of the American Academy of Orthopedic Surgeons; Journal of Arthroplasty; Journal of Bone and Joint Surgery (American and British Volumes); Journal of Orthopedic Trauma; Journal of Trauma; Orthopedics from AMEDEO.
Data collection and analysis
Selection of studies
Study selection was performed by one author.
Data extraction and management
Data for the outcomes listed above were independently extracted by both review authors using a data extraction form. Any differences were resolved by discussion.
Assessment of risk of bias in included studies
In the update of the review (2011), two aspects of risk of bias were assessed by one author (MJP) and reported. These were sequence generation and allocation concealment. In this assessment, incomplete or a lack of information on sequence generation or allocation concealment was judged as 'unclear' risk of bias unless the trial was quasi-randomised, in which case both were rated 'no'.
We also independently assessed 11 aspects of methodological quality using a slightly modified scheme to that used in former versions of the review (see Table 1). There was no masking of the study names or authors. Any differences were resolved by discussion.
Measures of treatment effect
Risk ratios and 95% confidence limits were calculated for dichotomous outcomes, and mean differences and 95% confidence limits calculated for continuous outcomes.
Assessment of heterogeneity
Heterogeneity between comparable trials was assessed by visual inspection of the overlap of confidence intervals amongst included studies and tested using a standard Chi² test.
Where appropriate, results of comparable groups of trials were pooled using the fixed-effect model. Where there was substantial heterogeneity, the results of the random-effects model were checked and presented.
We planned but did not undertake sensitivity analyses to investigate the effects of including trials which at risk of bias from lack of allocation concealment.
Description of studies
Thirty studies were included and details of these are given in the Characteristics of included studies. The included studies involve a total of 6334 patients (6339 fractures). Alho 1998 involved three hospitals with different randomisation of implants within each centre. Results for each centre in this study are therefore considered separately under three headings (Alho 1998(a); Alho 1998(b); Alho 1998(c)).
The majority of studies included both undisplaced and displaced fractures. Kuokkanen 1991 included only undisplaced fractures while Alho 1998 (Alho 1998(a); Alho 1998(b); Alho 1998(c)), Benterud 1997, Christie 1988, Frandsen 1981, Madsen 1987 and Paus 1986 included only displaced fractures. Dalen 1985 did not state the number of displaced fractures.
The types of implant studied differed considerably. Few studies compared the same implants. Details of comparisons can be found in the Characteristics of included studies, and are summarised under each comparison in Effects of interventions.
The authors of this report would be pleased to receive any additional information from any of the included studies which may then be included in updates of this review.
Risk of bias in included studies
The risk of bias assessments for sequence generation and allocation concealment for individual trials are shown in Figure 1 and an overall summary is given in Figure 2. The majority of judgements were 'unclear', which reflected in part the poor reporting of the methods of randomisation in these trials. Sequence generation was considered adequate in six trials. Only Lykke 2003 was judged as having adequate concealment of allocation. Four quasi-randomised trials (Harper 1992, Nordkild 1985, Stromquist 1988; Stromqvist 1984) were considered at high risk of bias resulting from both inadequate sequence generation and lack of allocation concealment. Details of the randomisation methods reported in the 30 trials are given below.
|Figure 1. Risk of bias summary: review authors' judgements about each risk of bias item for each included study.|
|Figure 2. Risk of bias graph: review authors' judgements about each risk of bias item presented as percentages across all included studies.|
Lagerby 1998 used closed sealed envelopes drawn in a sequential order. Elmerson 1988 randomised patients from a table of randomised numbers at the time of surgery. Alho 1998 (Alho 1998(a); Alho 1998(b); Alho 1998(c)) used random numbers within closed envelopes. Herngren 1992 and Elmerson 1995 also used a 'random numbers table'. Rehnberg 1989 also used random numbers but also matched for age, sex and type of residence. Wihlborg 1990 used sealed envelopes opened on the day of the operation. Lykke 2003 used sealed opaque numbered envelopes. Mjorud 2006 used sealed numbered envelopes. Paus 1986 used 'coded envelopes' and Sernbo 1990 used a random number generator to randomise the patient in the operating theatre. Parker 2010 used the toss of a coin.
Both Stromquist 1988 and Stromqvist 1984 used open randomisation with odd and even dates of birth. Nordkild 1985 stated they used 'odd and even numbers'. Harper 1992 used the even or odd medical record number.
Alberts 1989, Benterud 1997, Christie 1988, Dalen 1985, Frandsen 1981, Kuokkanen 1991, Lindequist 1989, Madsen 1987, Olerud 1991, Ovesen 1997, Svenningsen 1984, Sorensen 1992, and Sorensen 1996 did not give the method of randomisation. Holmberg 1990 stated that patients were randomised in the operating theatre but did not specify the method used.
The methodological assessment scores for the included studies are shown in Appendix 2.
Effects of interventions
For all the included studies the outcomes measures of non-union, avascular necrosis, total fracture healing complications, re-operations (for arthroplasty or implant removal), mortality and length of surgery are shown in the analysis tables. Data are not available from all included trials on all outcomes. Where significant results are reported in trials, these are also reported here.
Thornton nail versus three Scand pins
Dalen 1985 compared a single Thornton nail with three Scand pins in 94 patients. The limited results presented in the analyses indicate a tendency to a lower failure rate with the Scand pins ( Analysis 1.1, Analysis 1.2). Intracapsular pressures were measured for 21 of the cases and showed no difference in intra-operative intra-articular pressures.
Thornton nail versus sliding nail plate
Frandsen 1981 compared a single Thornton nail with a sliding nail plate in 383 patients. Results indicate a lower risk of non-union ( Analysis 2.1) for those fractures treated with a sliding nail plate but no statistically significant difference in avascular necrosis ( Analysis 2.2) or people with either complication ( Analysis 2.3).
Sliding compression screw implant versus McLaughlin nail plate
Svenningsen 1984 compared a sliding compression screw plate implant with a McLaughlin nail plate in 255 patients. Results indicate a tendency towards an increased non-union rate for those treated with the McLaughlin nail plate ( Analysis 3.1). There were no statistically significant differences between the two groups for avascular necrosis ( Analysis 3.2), all fracture healing complications ( Analysis 3.3), re-operations ( Analysis 3.4), infection ( Analysis 3.5) or mortality ( Analysis 3.6). Length of surgery was a mean of 43 minutes for the compression screw implant and 38 minutes for the McLaughlin nail plate (P < 0.001). Hospital stay and fall in haemoglobin were reported as showing no significant difference between groups.
Sliding hip screw (SHS) versus sliding nail plate
Nordkild 1985 compared the SHS with the sliding nail plate in 49 patients. Results indicate no difference in the incidence of fracture healing complications ( Analysis 4.1, Analysis 4.2) or re-operations (arthroplasty) ( Analysis 4.3) but an increased number of patients having residual pain in the nail plate group ( Analysis 4.4). Other outcomes reported were range of hip movements and walking aids used which showed no significant difference between groups. Bone scintigraphy was performed in a subgroup of 35 patients and showed no statistically significant difference between groups.
SHS versus double divergent pins
One study of 127 patients compared these implants (Christie 1988). The results for 15 patients were not given as they had either died early within the follow-up period or had been lost to follow-up. The data for non-union, avascular necrosis, re-operations (all for revision to arthroplasty) and use of walking aids at follow-up are given in the analyses. These results indicate a trend to a lower risk of non-union ( Analysis 5.1) and fewer re-operations ( Analysis 5.4) for those fractures fixed with the double divergent pins but no difference in the other outcomes.
SHS versus different types of cancellous bone screws
Eight studies compared the SHS with different types of cancellous bone screws (Benterud 1997; Harper 1992; Kuokkanen 1991; Madsen 1987; Ovesen 1997; Paus 1986; Sorensen 1992; Sorensen 1996). The results for the individual comparisons are described separately below but presented together in the analyses: Non-union ( Analysis 6.1), avascular necrosis ( Analysis 6.2), fracture healing complications ( Analysis 6.3), re-operations - arthroplasty ( Analysis 6.4), re-operations - implant removal ( Analysis 6.5), deep wound infection ( Analysis 6.6), mortality ( Analysis 6.7), and pain at follow-up ( Analysis 6.8).
SHS versus Uppsala/ Olmed screws
Benterud 1997 reported a study of 225 patients and found no difference in the incidence of fracture healing complications. Sorensen 1996 reported a study as a conference abstract for 101 patients and found no difference in the total incidence of fracture healing complications. Ovesen 1997 also reported a similar study only as a conference abstract for 316 fractures. The incidence of fracture healing complications for those who attended follow-up was reported as 31 per cent for the SHS and 25 per cent for Uppsala screws. The difference between these groups was reported as being not statistically significant. Re-operations for arthroplasty were required in 33/108 (30.6%) of SHS cases and 31/117 (26.5%) of the Uppsala group.
Benterud 1997 also reported that two patients in the SHS group developed wound infection requiring debridement. These were classified as deep wound infections in the analyses. Benterud 1997 found no difference between the two groups in mortality nor in pain at follow-up. Ovesen 1997 reported 'no difference' in mortality between groups at three, 12 and 24 months. The average hospital stay was 18 days in the SHS group and 15 days in the Uppsala screws group.
Benterud 1997 reported a significantly reduced median anaesthetic time for Olmed screws of 74 minutes versus 100 minutes for the SHS. Median operative times were 29 versus 55 minutes respectively. Ovesen 1997 reported median operative times of 25 minutes for Uppsala screws and 45 minutes for the SHS . Median operative blood loss was 10 ml for Uppsala screws and 100 ml for the SHS - this was reported as being statistically significant.
SHS versus two von Bahr screws
One study (Paus 1986) compared the SHS with two von Bahr screws in 131 patients. Results indicate no significant difference in any of the outcomes other than an increased number of patients treated with von Bahr screws who had implant removal ( Analysis 6.5). Length of surgery was also reported as showing a significant increase for the SHS (52 versus 41 minutes, P < 0.05).
SHS versus Gouffon screws
Sorensen 1992 compared the SHS with Gouffon screws in 73 patients. The trial was stopped earlier than planned because of the higher fixation failure rate in the Gouffon screw group. Results in the analyses shows a reduced fracture healing complications rate for the SHS (RR 0.52, 95% CI 0.31 to 0.87) but a higher mortality for SHS compared to the Gouffon screws (RR 2.53, 95% CI 1.09 to 5.86).
SHS versus three cancellous screws
Kuokkanen 1991 compared the SHS with three cannulated Mercon screws in 33 patients. Results for non-union, avascular necrosis, re-operations, deep wound infection and mortality are shown in the analyses with no significant difference for the different implants. In addition, there was one case of screw penetration into the acetabulum for the cancellous screw group. It was also reported there was no difference in the length of surgery between groups (61 minutes in each group). Mean operative blood loss was 200 ml for the cancellous screws and 245 ml for the SHS. The surviving patients were assessed by the Harris Hip Score (Harris 1969) - the results were stated to be 'somewhat better' for the SHS group (3/14 fair or poor for the SHS versus 6/15 for cancellous screws).
Harper 1992 compared the SHS (Ambi screw) with three cancellous screws in 209 patients. Only limited outcomes were reported. The number of cases requiring arthroplasty for fracture healing complications was 9/102 in the SHS group and 11/107 in the cancellous screw group. In addition there were two cases of fracture below the cancellous screws. There was no difference in mortality between groups.
SHS versus four cancellous screws
Madsen 1987 compared the SHS with four cancellous AO screws in 103 patients. Results for non-union of the fracture were presented using an actuarial survival analysis from which it was not possible to determine the number of patients who had died, been lost to follow-up or developed non-union. The paper reported a two-year cumulated union rate of 64 per cent for the SHS and 84 per cent for the parallel screw group, a difference that was reported as being statistically significant (P < 0.05). Results for avascular necrosis, re-operations and deep wound infection given in the analyses show no significant differences.
Madsen 1987 also reported on length of surgery which was a mean of 130 minutes for the SHS and 108 minutes for the parallel screws. Figures for the mean operative blood loss were 350 ml versus 200 ml for the cases of SHS and parallel screws who had a general anaesthetic and 200 ml versus 150 ml for those who had a regional anaesthetic. All these differences between groups were significantly in favour of the cancellous screws. Bone scintigraphy was also measured in 87 cases in Madsen 1987. The number of femoral heads with an impaired uptake was 14/40 for the SHS and 5/47 for the cancellous screws, a difference that was reported to be statistically significant.
Two von Bahr screws versus Hessel pins
Lindequist 1989 compared von Bahr screws with Hessel pins for 150 patients. All the results of this study are presented in the analyses ( Analysis 7.1 to Analysis 7.8) and indicate a reduction in fracture healing complications (RR 0.58, 95% CI 0.40 to 0.83, Analysis 7.3) and re-operations (RR 0.47, 95% CI 0.28 to 0.79, Analysis 7.4; RR 0.26, 95% CI 0.10 to 0.66, Analysis 7.5) for the von Bahr screws.
Two von Bahr screws versus Gouffon screws
Lindequist 1989 compared von Bahr screws with Gouffon screws in 169 patients. All the results of this study are presented in the analyses ( Analysis 8.1 to Analysis 8.8) and indicate no significant difference in the incidence of fracture healing complications but a reduction in re-operations for implant removal ( Analysis 8.5) for the von Bahr screws.
Two von Bahr screws versus two Uppsala screws
One study of 222 patients compared these two implants (Rehnberg 1989). Results indicate a higher risk of non-union and fracture healing complications for the von Bahr screws (RR 3.18, 95% CI 1.70 to 5.94, Analysis 9.1; RR 2.17, 95% CI 1.32 to 3.55, Analysis 9.3). In addition to the complications shown in the analyses there were two cases of screw penetration in the Uppsala group and one in the von Bahr group. Other outcomes reported were for mortality Analysis 9.6), mean length of surgery and mean operative blood loss for which there was no significant difference between groups. Pain was assessed at four and 12 months and reported to be significantly reduced for those treated with Uppsala screws (P < 0.001 at 4 months, P < 0.01 at 12 months). Use of walking aids was reported to be significantly more common (P < 0.01) after von Bahr screws at four months, but no significant difference was noted at 12 months. There was no significant difference in the change in residential status between groups for four and 12 months.
Three Richard screws versus two Uppsala screws
Lagerby 1998 studied 268 fractures in 266 patients. Results for non-union ( Analysis 10.1), avascular necrosis ( Analysis 10.2), fracture healing complications ( Analysis 10.3) and pain at follow-up ( Analysis 10.4) show no significant difference between the two implants. Re-operations, mortality and use of walking aids were reported as showing 'no difference' between groups.
Three Ullevaal screws versus two Olmed screws
Alho 1998(a) and Alho 1998(c) compared three Ullevaal screws with two Olmed screws in 358 patients. The limited results as presented in the analyses show a lower re-operation rate for conversion to arthroplasty for those patients treated at Ullevaal hospital (Alho 1998(c); RR 0.42, 95% CI 0.22 to 0.83, Analysis 11.1). No difference in this re-operation rate was seen at the other centre (Alho 1998(a)). There was no difference between the two interventions in the implant removal rate ( Analysis 11.2). Three patients in the Ullevaal screw group and one in the Olmed screw group suffered fracture below the screws, necessitating revision fixation ( Analysis 11.3). No other outcomes were reported.
Three Ullevaal screws versus two Tronzo screws
Alho 1998(b) compared three Ullevaal screws with two Tronzo screws in 249 patients. The limited results, as presented in the analyses, indicate no difference in the number of patients needing conversion to arthroplasty ( Analysis 12.1), but a tendency to a lower removal of the implant for the Tronzo screws, although the result did not reach statistical significance (RR 2.05, 95% CI 0.90 to 4.66, Analysis 12.2). One patient in the Ullevaal screw group suffered fracture below the screws, necessitating revision fixation ( Analysis 12.3). No other outcomes were reported.
Three screws of any type versus two screws of any type
Exploratory analysis was undertaken to combine all studies which compared three screws with two screws (Alho 1998(a); Alho 1998(b); Alho 1998(c); Lagerby 1998). Results as indicated in the analyses ( Analysis 13.1 to Analysis 13.8) show no significant difference between three or two screws except for re-operation for arthroplasty. For this outcome there was a significant reduction for the three screws (32/302 versus 52/305: RR 0.64, 95% CI 0.43 to 0.97, Analysis 13.4). However, when those cases of non-union in Lagerby 1998 are considered as well, the difference in major fracture healing complications between three and two screws becomes statistically insignificant ( Analysis 13.7).
Three short threaded AO screws versus three long threaded AO screws
Parker 2010 compared three AO screws with 16 mm of threads with three AO screws of 32 mm threads in 432 patients. Results as presented in the analyses showed no statistically significant differences in the occurrence of fracture healing complications ( Analysis 14.1, Analysis 14.2, Analysis 14.3), re-operations ( Analysis 14.4, Analysis 14.5), mortality ( Analysis 14.6), residual pain ( Analysis 14.7) or change in residential status ( Analysis 14.8) between the two methods of fixation. In addition there was no difference between groups for the regain of mobility and mean pain scores at one year from injury.
Three Scand screws versus three Nystrom nails
Alberts 1989 compared three Nystrom nails with three Scand screws in 133 patients. Results as presented in the analyses showed no difference for fracture healing complications ( Analysis 15.1, Analysis 15.2, Analysis 15.3), infection ( Analysis 15.4, Analysis 15.5) and mortality ( Analysis 15.6, Analysis 15.7). Extrusion of the implant was more common with the Nystrom nails. Mean length of surgery was 18 minutes for the Nystrom nails and 30 minutes for the Scand screws (P value reported as < 0.001).
Three Gouffon screws with a Rydell four-flanged nail
Two studies compared these two implants. Elmerson 1988 reported a study of 223 patients and Wihlborg 1990 a study of 200 patients. Results as presented in the analyses showed no difference between the two implants for the outcome measures of non-union ( Analysis 16.1), avascular necrosis ( Analysis 16.2), fracture healing complications ( Analysis 16.3), re-operations (for arthroplasty) ( Analysis 16.4), infection ( Analysis 16.5, Analysis 16.6) or mortality ( Analysis 16.7, Analysis 16.8).
Elmerson 1988 also indicated that the mean length of surgery was 38 minutes for Gouffon screws and 28 minutes for the Rydell nail, a difference that was reported to be statistically significant (P < 0.001).
Two Hansson pins versus a Rydell four-flanged nail
Three studies compared these implants: Holmberg 1990 reported a study of 220 patients; Sernbo 1990 of 410 patients and Stromqvist 1984 of 152 patients. The outcomes measures, where reported, for non-union ( Analysis 17.1), avascular necrosis ( Analysis 17.2), fracture healing complications ( Analysis 17.3), re-operations ( Analysis 17.4, Analysis 17.5) and mortality at two years ( Analysis 17.6) are shown in the analyses. Results indicated no significant difference in outcomes between the two implants for any of the outcomes listed above; the random-effects model was used for the first five analyses because of clearly significant heterogeneity.
Holmberg 1990 reported that a similar number of patients in each group (27/110 and 26/110) failed to return to the same residential status. Sernbo 1990 also gave figures for the mean length of surgery, radiographic screening time, length of hospital stay and numbers going back to the same residential state. There was no significant difference between groups for any of these outcomes. Stromqvist 1984 reported no cases of deep wound infection in either group and also presented the results of bone scintimetric evaluation for 138 of the patients. This indicated a statistically significant reduction of uptake of isotope for those fractures treated with the four-flanged nail.
Two Hansson pins versus Sliding Hip Screw (SHS)
Both Elmerson 1995 (222 patients) and Sorensen 1996 (99 patients) found no difference in the incidence of fracture healing complications ( Analysis 18.1, Analysis 18.2, Analysis 18.3), or re-operations ( Analysis 18.4). Mortality was reported in Elmerson 1995 with no difference between implants ( Analysis 18.5). Elmerson 1995 also reported on the length of surgery, which was significantly lower for the Hansson pins (24 versus 34 minutes, Analysis 18.6).
Two Hansson hook pins versus cancellous screws
Six studies compared two Hansson hook pins with different types of cancellous bone screws (Herngren 1992; Lykke 2003; Mjorud 2006; Olerud 1991; Sorensen 1996; Stromquist 1988). The results for the individual comparisons are described separately below but presented together in the analyses: Non-union ( Analysis 19.1), avascular necrosis ( Analysis 19.2), fracture healing complications ( Analysis 19.3), re-operations - arthroplasty ( Analysis 19.4), re-operations - arthroplasty or need for arthroplasty ( Analysis 19.5), re-operations - implant removal ( Analysis 19.6), re-operations - type not specified ( Analysis 19.7), deep wound infection ( Analysis 19.8), superficial wound infection ( Analysis 19.9), and mortality ( Analysis 19.10).
Two Hansson pins versus two Uppsala screws
Three studies compared these implants: Herngren 1992 (179 patients, 180 fractures), Olerud 1991 (115 patients) and Sorensen 1996 (100 patients). Pooled results using the random-effects model for non-union, avascular necrosis and all fracture healing complications show no significant differences between the two implants. Notably, Olerud 1991 reported a significant reduction in the incidence of non-union for those treated with the Uppsala screws (RR 3.79, 95% CI 1.51 to 9.53), while the two trials (Herngren 1992; Sorensen 1996) found no difference between implants for the incidence of fracture healing complications. Herngren 1992 also reported three cases of trochanteric fracture of the same hip in those treated with the Hansson pins and one case with Uppsala screws. Pooled data for mortality from two trials showed trend to lower mortality in the Hansson pin group.
Length of surgery reported by Herngren 1992 was a mean of 33 minutes for the Hansson pins and 38 minutes for the Uppsala screws.
Olerud 1991 also reported, without figures, that at the four and 12 month follow-up there was a statistically significant increased incidence of pain (P = 0.0007 at 4 months, P = 0.007 at 12 months), failure to regain residential status (P = 0.028 at 4 months, P = 0.03 at 12 months) and reduction in mobility (P = 0.008 at 4 months, P = 0.097 at 12 months) for those treated by the Hansson pins.
Herngren 1992 noted there was local discomfort to lateral protrusion of the implant in six out of 96 Uppsala screw cases but in no patients of the Hansson group.
Two Hansson hook pins versus two AO screws
Stromquist 1988 studied 110 cases. Follow-up of patients was for only four months and the trial methodology was poor. Non-union and avascular rates were not given but re-operations within the follow-up period were stated as fewer for the Hansson pins. However, it was reported that more patients in the Hansson pin group were scheduled for arthroplasty, such that the difference between groups for those who had re-operations and needed re-operation was not significantly different (Analysis 19.5). Mortality and bone scintimetry results showed no significant difference between the two implants.
Two Hansson hook pins versus three AO screws
Mjorud 2006 studied 199 cases. Follow-up of patients was for two years. Outcomes reported and detailed in the analyses were fracture healing complications and re-operations. None of these outcomes showed any difference between groups. Mean length of surgery was 36 minutes for the Hansson pins and 40 minutes for the AO screws, a difference that was reported as not statistically significant. Mortality reported at up to two years from surgery showed no difference between groups. Other outcomes reported which also showed no statistically significant difference between groups were inability to walk at discharge and later walking ability.
Two Hansson hook pins versus three Ullevaal screws
Lykke 2003 compared two Hansson pins with three Ullevaal screws in 278 fractures. Results as indicated in the analyses show no significant difference in non-union, fracture healing complications, re-operations, wound infections or mortality between treatment groups. There appeared, however, a potential trend to a lower rate of avascular necrosis in the Hansson pin group. In addition the study reported there was no differences in the degree of residual pain at follow-up between groups (31% versus 23%), mean or median length of hospital stay (12 versus 10 days, 8 versus 8 days), or proportion of patients discharged to rehabilitation homes (47% versus 49%). The complication of deep vein thrombosis was similar between groups (one in each) as was that from pneumonia (one in the Hansson pin group versus three in the Ullevaal group). Fracture healing complications were more common in those cases in which drill penetration into the hip joint occurred during surgery. Drill penetration was more common in the Ullevaal screw group (7 versus 16 cases).
Thirty studies using a wide variety of orthopaedic implants were identified and included within the analysis. The methodology of the studies varied considerably and most trials scored poorly, although in some of these cases the low score may reflect a poor reporting of trial methods rather than poor trial methodology. Additionally, risk of bias assessment relating to sequence generation and allocation concealment found only six trials were at low risk of bias for the first item and only one trial at low risk of bias for the second. The main outcome measures reported were fracture healing complications, re-operations and mortality. The reporting of functional outcomes was poor and only documented in a small number of studies. The few significant differences observed after multiple analyses may have arisen by chance. Taken in conjunction with the generally low methodological quality of the studies as reported, caution needs to be adopted in drawing any definite conclusions. Most of the reported trials enrolled less than 300 participants. Thus, they were likely to be underpowered to provide evidence of significant difference between devices unless these differences had been expected to be large. Biologically or mechanically plausible differences between devices compared, and thus the hypotheses apparently being tested in the trials, were often unclear.
A significant potential for bias within the studies may have occurred in those centres which were evaluating an implant that was developed in their own institution, or by one of the authors of the study. The studies concerned were for Hansson pins (Stromqvist 1984), Uppsala screws (Olerud 1991; Rehnberg 1989), sliding compression screw plate (Svenningsen 1984) and Ullevaal screws (Alho 1998(c)). All these reported better outcomes for their own implants. The problems are highlighted in Alho 1998 who recommends that evaluation of implants by centres with a particular interest or expertise in one of the implants, is strongly prone to biases even within the context of a randomised trial. The cause for these biases is difficult to explain.
The conclusions for the different implants are summarised in the following.
Double divergent pins; fixed (static) nail plate; sliding compression screw plate; Hessel pins and Nystrom nails
For all these implants, only one randomised trial was found evaluating each implant (Alberts 1989: Nystrom nails; Christie 1988: double divergent pins; Lindequist 1989: Hessel pins; Svenningsen 1984: fixed nail plate and sliding compression screw plate). None of these studies showed a clear difference between the implants under investigation. Therefore, no conclusions can be made for the use of these implants from the randomised trials undertaken to date.
Single Thornton nail
This implant was found to have been evaluated in two randomised studies; one against three cancellous screws (Dalen 1985) and another against a sliding nail plate (Frandsen 1981). Both studies reported a tendency to a lower risk of fracture healing complications with the comparison implant. While there are limited data on the use of this implant, its use cannot be recommended given the tendency to inferior results in both comparisons.
Sliding nail plate
This implant has been evaluated in two randomised studies, one against a single Thornton nail (Frandsen 1981), where a lower rate of non-union was found for the nail plate, and the other against an SHS (Nordkild 1985), where more patients had residual pain in the nail plate group. However, the small number of patients evaluated within these two trials means that no definite conclusions can be made regarding the use of a sliding nail plate.
Rydell four-flanged nail
This implant was found to have been evaluated in five randomised studies, two comparing against Gouffon pins (Elmerson 1988; Wihlborg 1990) and three studies comparing against Hansson pins (Holmberg 1990; Sernbo 1990; Stromqvist 1984). No difference for the incidence of fracture healing complications or mortality between groups was found. As exception was found for Stromqvist 1984, where the results favoured the Hansson pin but, as stated already, this trial is potentially biased given the implant had been developed in the same institution.
Hansson hook (LIH) pins
This implant has been evaluated in 10 randomised trials. Bias may have occurred in these studies, possibly due to greater experience with one of the implants under investigation. A strong trend to improved outcomes with the Hansson pins was found in the study from Lund, Sweden (Stromqvist 1984), where the pins were developed by one of the paper's authors. The study from Uppsala, Sweden (Holmberg 1990) was from a unit where the Rydell nail was the implant used before the start of the study. This study showed a tendency to lower complications with the Rydell nail. A study from Uppsala (Olerud 1991) compared Hansson pins with Uppsala screws and found better outcomes with the latter group. The difference in results between studies may therefore be due to familiarity or special expertise with the use of one of the implants under investigation.
Three studies compared Hansson pins with the Rydell nail (Holmberg 1990; Sernbo 1990; Stromqvist 1984). Although, as described above, Stromqvist 1984 showed better outcomes after the Hansson pins, overall there were no notable differences between implants. Three studies compared Hansson pins with Uppsala screws (Herngren 1992; Olerud 1991; Sorensen 1996), two with two AO screws (Mjorud 2006; Stromquist 1988), one with Ullevaal screws (Lykke 2003) and two with the SHS (Elmerson 1995; Sorensen 1996). Overall there were no notable differences in fracture healing complications between implants.
Sliding hip screw (SHS)
This implant has been evaluated more extensively within 11 randomised studies. Christie 1988 compared the SHS with double divergent pins. There was a tendency to lower fracture healing complications after double divergent pins, but due to the low numbers of patients reported, no definite conclusions can be made about the comparison of these two implants. Nordkild 1985 compared the SHS with the sliding nail plate. Results indicated no difference in the incidence of fracture healing complications, but more patients had residual pain in the nail plate group. Two studies compared the SHS with Hansson pins (Elmerson 1995; Sorensen 1996). Neither study found any significant difference in the incidence of fracture healing complications.
Eight studies compared the SHS with different types of cancellous bone screws (Benterud 1997; Harper 1992; Kuokkanen 1991; Madsen 1987; Ovesen 1997; Paus 1986; Sorensen 1992; Sorensen 1996). Summation of results showed an increased incidence of avascular necrosis and also a tendency to a higher fixation failure rate with the cancellous screws, although the overall re-operation rate for fixation failure did not differ between implants. Those studies that reported on operative blood loss and operative time noted an increase for the SHS. The findings of a significantly higher mortality in the SHS group of Sorensen 1992 were not found in the other five trials providing data for this outcome.
Implants consisting of multiple screws were the most prevalent type of implant studied. Eighteen studies compared a multiple parallel screw technique against an alternative type of implant. As summarised above, for those studies that compared multiple screws against the SHS (Benterud 1997; Harper 1992; Kuokkanen 1991; Madsen 1987; Ovesen 1997; Paus 1986; Sorensen 1992; Sorensen 1996), there was no overall difference in the number of fracture healing complications between implants aside from an increased incidence of avascular necrosis for the screws, but some studies noted that the SHS fixation took longer and had an increased blood loss. For those studies, which compared parallel screws with another type of implant, no study demonstrated notable differences for these comparisons. These studies were those comparing Gouffon screws with the Rydell nail (Elmerson 1988; Wihlborg 1990), Uppsala/Olmed screws with Hansson pins (Olerud 1991; Sorensen 1996; Herngren 1992), AO screws with Hansson pins (Mjorud 2006; Stromquist 1988), Ullevaal screws with Hansson pins (Lykke 2003), Scand hip pins with the Thornton nail (Dalen 1985), Scand hip pins with Nystrom nails (Alberts 1989) and von Bahr screws with Hessel pins (Lindequist 1989).
A further five studies compared different screw types (Alho 1998 (Alho 1998(a); Alho 1998(b); Alho 1998(c)); Lagerby 1998; Lindequist 1989; Rehnberg 1989; Parker 2010). For these studies it was not possible to make any notable conclusions between the different screw types affecting the incidence of fracture healing complications. This included those studies which compared two versus three screws.
Implications for practice
There is insufficient evidence from randomised controlled trials to determine the best implant for internal fixation of intracapsular fractures.
Implications for research
Further studies are required to determine the choice of implant for internal fixation of intracapsular fractures. Future studies should be adequately powered to detect any clinically important difference between implant types; in the light of the evidence from this review, they may require recruiting thousands rather than hundreds of participants, and to be multi-centre in order to increase generalisability and avoid biases which may have arisen in the past from single centre studies. These trials should have appropriate methodology with a minimum of one year follow-up of cases and always report the results in full, even if the difference between implants is not significant. The current ongoing multi-centre FAITH trial (FAITH) does address these issues and is comparing the two most commonly used implants of the SHS and multiple screws.
Glyn Stockton was co-author for the first edition of this review. Helen Handoll independently extracted data and checked the study of Parker 2010. We are indebted to Prof William Gillespie, Leeann Morton and Dr Helen Handoll for their help. We would also like to thank the following for useful comments from editorial review: Prof Rajan Madhok, Prof Gordon Murray, Prof Marc Swiontkowski, Dr Janet Wale, Peter Herbison, Prof James Hutchison, Dr Dicky Lam and Dr Jean-Claude Theis.
Data and analyses
- Top of page
- Authors' conclusions
- Data and analyses
- What's new
- Contributions of authors
- Declarations of interest
- Sources of support
- Differences between protocol and review
- Index terms
Appendix 1. Search strategies
Cochrane Central Register of Controlled Trials (Wiley Online Library)
#1 MeSH descriptor Hip Fractures explode all trees (927)
#2 ((hip* or femur* or femoral* or intracapsular* or subcapital or transcervical) NEAR/4 fracture*):ti,ab,kw (1952)
#3 (#1 OR #2) (1952)
#4 (pin or pins or pinned or pinning or nail* or screw* or plate* or arthroplast* or fix* or prosthes*):ti,ab,kw (29319)
#5 MeSH descriptor Internal Fixators, this term only (98)
#6 MeSH descriptor Bone Screws, this term only (394)
#7 MeSH descriptor Fracture Fixation, Internal explode all trees (652)
#8 MeSH descriptor Bone Plates, this term only (212)
#9 MeSH descriptor Bone Nails, this term only (250)
#10 MeSH descriptor Arthroplasty, this term only (139)
#11 MeSH descriptor Arthroplasty, Replacement, Hip, this term only (1172)
#12 (#4 OR #5 OR #6 OR #7 OR #8 OR #9 OR #10 OR #11) (29319)
#13 (#3 AND #12) (745)
#14 (extracapsular or trochanteric or subtrochanteric or pertrochanteric or intertrochanteric):ti (389)
#15 (intracapsular or subcapital or transcervical):ti (225)
#16 (#14 AND NOT #15) (379)
#17 (#13 AND NOT #16) (499)
MEDLINE (Ovid Web)
1 exp Hip Fractures/ (14794)
2 ((hip$ or femur$ or femoral$ or intracapsular$ or subcapital or transcervical) adj4 fracture$).tw. (20570)
3 or/1-2 (24920)
4 (pin$1 or nail$ or screw$1 or plate$1 or arthroplast$ or fix$ or prosthes$).tw. (385604)
5 Internal Fixators/ or Bone Screws/ or Fracture Fixation, Internal/ or Bone Plates/ or Bone Nails/ (40241)
6 Arthroplasty/ or Arthroplasty, Replacement, Hip/ (17548)
7 or/4-6 (404588)
8 and/3,7 (10370)
9 (extracapsular or trochanteric or subtrochanteric or pertrochanteric or intertrochanteric).ti. (3536)
10 (intracapsular or subcapital or transcervical).ti. (1753)
11 9 not 10 (3458)
12 8 not 11 (9105)
13 Randomized Controlled Trial.pt. (298721)
14 Controlled Clinical Trial.pt. (82422)
15 randomized.ab. (205154)
16 placebo.ab. (121719)
17 Clinical Trials as Topic.sh. (150826)
18 randomly.ab. (149185)
19 trial.ti. (88477)
20 13 or 14 or 15 or 16 or 17 or 18 or 19 (692318)
21 exp Animals/ not Humans/ (3531211)
22 20 not 21 (640356)
23 12 and 22 (461)
EMBASE (Ovid Web)
1 exp Hip Fracture/ (20636)
2 ((hip$ or femur$ or femoral or intracapsular$ or subcapital or transcervical) adj4 fracture$).tw. (23792)
3 or/1-2 (31432)
4 (pin$1 or nail$ or screw$1 or plate$1 or arthroplast$ or fix$ or prosthes$).tw. (434374)
5 Bone Nail/ or Bone Plate/ or Bone Screw/ or Ender Nail/ or External Fixator/ or Fixation Device/ or Interlocking Nail/ or Internal Fixator/ or Osteosynthesis Material/ (26043)
6 exp Fracture Fixation/ (52878)
7 Arthroplasty/ or Hip Arthroplasty/ (18137)
8 or/4-7 (465804)
9 and/3,8 (13255)
10 (extracapsular or trochanteric or subtrochanteric or pertrochanteric or intertrochanteric).ti. (4058)
11 (intracapsular or subcapital or transcervical).ti. (1907)
12 10 not 11 (3967)
13 9 not 12 (11698)
14 Randomized Controlled Trial/ (280313)
15 Clinical Trial/ (804967)
16 Controlled Clinical Trial/ (161695)
17 Randomization/ (52313)
18 Single Blind Procedure/ (13269)
19 Double Blind Procedure/ (98937)
20 Prospective Study/ (154609)
21 ((clinical or controlled or comparative or prospective$ or randomi#ed) adj3 (trial or study)).tw. (508940)
22 (random$ adj7 (allocat$ or allot$ or assign$ or basis$ or divid$ or order$)).tw. (126704)
23 ((singl$ or doubl$ or trebl$ or tripl$) adj7 (blind$ or mask$)).tw. (126329)
24 ((allocat$ or allot$ or assign$ or divid$) adj3 (condition$ or experiment$ or intervention$ or treatment$ or therap$ or control$ or group$)).tw. (150805)
25 RCT.tw. (5874)
26 or/14-25 (1373779)
27 Case Study/ or Abstract Report/ or Letter/ (762331)
28 26 not 27 (1345199)
29 13 and 28 (1397)
Appendix 2. Methodological quality assessment results
Last assessed as up-to-date: 5 November 2010.
Protocol first published: Issue 2, 1999
Review first published: Issue 4, 2001
Contributions of authors
Martyn Parker initiated and designed the review, read all studies, extracted data and compiled the first drafts. Kurinchi Gurusamy checked data from the newly studies identified for the first and second update. Martyn Parker is the guarantor of the review.
Declarations of interest
Martyn Parker was the lead author of one of the studies included in this review (Parker 2010). The assessment of this study was undertaken by Kurinchi Gurusamy and Helen Handoll. Martyn Parker has received and may continue to receive financial payment from manufacturing companies of orthopaedic implants used for the internal fixation of hip fractures and for attending meeting organised by these companies and for advising on the design and use of hip fracture implants. Kurinchi Gurusamy has no connection with any manufacturing company.
Sources of support
- Scottish Home and Health Department, UK.
- No sources of support supplied
Differences between protocol and review
In the update of the review (2011), two aspects of risk of bias were assessed and reported: sequence generation and allocation concealment. We also modified our former scheme for assessment methodological quality, mainly adding in an item for sequence generation.
Medical Subject Headings (MeSH)
MeSH check words
* Indicates the major publication for the study