Outcomes of dual-mobility total hip arthroplasty versus bipolar hemiarthroplasty for patients with femoral neck fractures: a systematic review and meta-analysis.

Background: Elderly patients with femoral neck fractures are at a higher risk of dislocation after hip arthroplasty procedures. In comparison with total hip arthroplasty (THA), bipolar hemiarthroplasty (HA) and dual-mobility total hip arthroplasty (DM-THA) can be an effective alternative treatment which increases the effective head size and overall stability of the prosthesis. We aim to review the current evidence on the outcome after DM-THA and HA for femoral neck fractures in the elderly.

Methods: We performed a comprehensive review of literatures on PubMed, Embase, Web of Science, and the Cochrane Library for randomized controlled trials and comparative interventional studies. Of the 936 studies identified, 8 met the inclusion criteria (541 DM-THA and 603 HA procedures). Two reviewers independently reviewed and graded each study and recorded relevant data including dislocation rate, implant failure rate, reoperation rate, 1-year mortality rate, Harris hip score (HHS), operation time, and intraoperative blood loss.

Results: DM-THA was associated with a lower dislocation rate (OR 3.599; 95% CI 1.954 to 6.630), a lower reoperation rate (OR 2.056; 95% CI 1.211 to 3.490), an increased operation time (SMD - 0.561; 95% CI - 0.795 to - 0.326) and more intraoperative blood loss (SMD - 0.778; 95% CI - 1.238 to - 0.319), compared with the HA group. Moreover, the multivariate regression analysis revealed that age, female sex, posterolateral surgical approach, and choice of DM-THA or HA were not associated with dislocation or reoperation.

Conclusions: Based on the current evidence, the advantages reported for DM-THA over HA with regard to dislocation and reoperation rate in elderly patients with FNF remain inconclusive. High-quality studies on the high-risk patients with cognitive disorder or dementia are necessary to validate the value of DM-THA.