|A meta-analysis of the Gamma nail and dynamic hip screw in treating peritrochanteric fractures
|Liu M, Yang Z, Pei F, Huang F, Chen S, Xiang Z
The review found there was a higher rate of postoperative femoral shaft fracture with Gamma nail compared with dynamic hip screw fixation in treating peritrochanteric fractures, but no differences for other outcomes; further research is needed. The authors' conclusions reflect the data presented, but should be interpreted considering the substantial methodological flaws in included trials and potential review process bias.
To compare the effectiveness of Gamma nail versus dynamic hip screw internal fixation devices for the fixation of peritrochanteric fractures.
MEDLINE, EMBASE, and Current Contents were searched from inception to August 2008; the Cochrane Musculoskeletal Injuries Group Trials Register was also searched in August 2008. Search terms were not reported. Orthopaedic journals were handsearched.
Eligible studies were prospective randomised or pseudo-randomised controlled trials (RCTs) of individuals with peritrochanteric fractures classified as peritrochanteric or intertrochanteric, with or without subtrochanteric extension, excluding pathological fractures, where dynamic hip screw fixation was compared with Gamma nail fixation.
The outcomes of interest were complications during follow-up, including wound infection rate, mortality, postoperative femoral shaft fracture, reoperation rate for fracture fixation failure, and percentage of participants walking independently after rehabilitation.
In the included trials, the average age of participants ranged from 78 to 83 years; most were female and Caucasian. Over half of the included trials were conducted in the UK.
Two reviewers independently selected studies for the review, with differences resolved by discussion.
Assessment of study quality
Trials were assessed for quality according to the similarity of groups at baseline, randomisation method, allocation concealment, blinding, and loss to follow-up. Each criterion was scored according to Cochrane Collaboration methods as A (adequate), B (unclear), C (inadequate), or D (not used). The overall rating of each trial was the allocation concealment score.
It was not explicitly reported how quality assessment of the included studies was undertaken, although it was likely that it was performed by two independent reviewers following Cochrane Collaboration guidelines.
Relative risks (RRs) with 95% confidence intervals (CIs) for dichotomous data and weighted mean differences (WMDs) with 95% confidence intervals for continuous data were extracted.
It was not explicitly reported how data extraction was undertaken, although it was likely that this was performed by two independent reviewers following Cochrane Collaboration guidelines
Methods of synthesis
Tria;s were pooled in meta-analyses using a fixed-effects model, where there was no evidence of heterogeneity. When heterogeneity was evident, a random-effects model was used. Heterogeneity was assessed using X2 and I2.
Results of the review
Seven RCTs (number of participants not reported; number of fractures=1,257) were included in the review. All trials received an overall rating of B, which indicated that allocation concealment was unclear. Length of follow-up ranged from six to 12 months (where reported).
There was no evidence of a statistical difference between fixation methods in the rate of wound infection (RR 1.02, 95% CI 0.56 to 1.86; seven RCTs), mortality (RR 1.0, 95% CI 0.81 to 1.24; six RCTs), reoperation rate (RR 1.64, 95% CI 0.91 to 2.95; four RCTs), or walking independently (RR 0.89, 95% CI 0.60 to 1.33; two RCTs). Postoperative femoral shaft fracture was significantly more likely with Gamma nail than with dynamic hip screw fixation (RR 7.27, 95% CI 2.83 to 18.70; seven RCTs). There was no evidence of heterogeneity in most analyses, except for independent walking rate (X2 p=0.08; I2=68%).
Although there was a higher rate of postoperative femoral shaft fracture with Gamma nail compared with dynamic hip screw fixation, there was a need for further research to more adequately compare the two procedures.
The review addressed a clear research question and inclusion criteria appear appropriate. A range of sources were used to search for published studies. However, the search was restricted to English language and no attempts were made to identify unpublished studies, so language and publication bias could not be ruled out. Appropriate methods appear to have been used to select studies, extract data and assess the quality of included studies, but lack of reporting meant that reviewer error and/or bias could not be ruled out.
The criteria used to assess trials for quality were appropriate, but the included trials had substantial methodological flaws. The synthesis of results in meta-analyses was appropriate. It was not clear whether participants had multiple fractures, as the numbers of participants in the trials were not reported; analyses of some outcomes by fractures rather than participants suggested that unit of analysis errors could not be excluded.
The authors' conclusions reflect the data presented, but must be interpreted in light of substantial methodological flaws in the included trials and potential bias in the review process.
Implications of the review for practice and research
Practice: The authors stated that dynamic hip screw fixation is a safer and more dependable procedure than Gamma nail fixation and may be the first option for the treatment of peritrochanteric fractures.
Research: The authors stated that more high quality RCTs need to be performed to evaluate changes in design to the fixation methods.
National Basic Research Program of China, contract grant number G2005cb623901); National Natural Sciences Foundation of China, grant number 30271317.
Liu M, Yang Z, Pei F, Huang F, Chen S, Xiang Z. A meta-analysis of the Gamma nail and dynamic hip screw in treating peritrochanteric fractures. International Orthopaedics 2010; 34(3): 323-328
Subject indexing assigned by NLM
Bone Nails; Bone Screws; Femoral Fractures /etiology; Fracture Fixation, Internal /instrumentation /methods /rehabilitation; Hip Fractures /mortality /physiopathology /surgery; Humans; Postoperative Complications; Randomized Controlled Trials as Topic; Reoperation; Survival Rate; Treatment Outcome; Walking
Database entry date
This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.