Bipolar versus unipolar hemiarthroplasty for displaced femoral neck fractures in the elder patient: a systematic review and meta-analysis of randomized trials.

OBJECTIVE: To assess the safety and efficacy that compare bipolar hemiarthroplasty with unipolar hemiarthroplasty for the treatment of femoral neck fracture in the patient aged more than 65 years.

METHODS: We searched databases including PubMed Central, MEDLINE (from 1966), EMBASE (from 1980) and the Cochrane Central Register of Controlled Trials database. Only prospective randomized controlled trials (RCTs) that compare bipolar hemiarthroplasty with unipolar hemiarthroplasty for the treatment of femoral neck fracture in the elder patient were included. RevMan 5.2 from the Cochrane Collaboration was applied to perform the meta-analysis.

RESULTS: Six relevant RCTs with a total of 982 patients were retrieved. From this meta-analysis, mortality rates showed no statistical difference between two treatments, 14.7% for bipolar versus 13.8% for unipolar. The acetabular erosion rates were significantly different between two groups (P=0.01), 1.2% in bipolar versus 5.5% in unipolar group. Overall complication rates, dislocation rates, infection rates and reoperation rates between two groups showed no statistical difference (P>0.05). Neither of two treatments appeared to be superior regarding the clinical function assessed by Harris hip scores or return to pre-injury state rates (P>0.05).

CONCLUSIONS: Both bipolar and unipolar hemiarthroplasty for the treatment of elderly patient suffering displaced femoral neck fracture achieve similar and satisfy clinical outcome in short-term follow-up. Unipolar hemiarthroplasty seems to be a more cost-effectiveness option for elderly patient.