Patients with femoral neck fractures treated by bipolar hemiarthroplasty have superior to unipolar hip function and lower erosion rates and pain: a systematic review and meta-analysis of randomized controlled studies

Abstract

Purpose: We assessed acetabular erosion, hip function, quality of life (QoL), pain, deep infection, mortality, re-operation and dislocation rates in patients with displaced femoral neck fractures (dFNFs) treated with unipolar versus bipolar hemiarthroplasty at different postoperative time points.

Methods: Relevant Randomized Controlled Trials (RCTs) were identified, following comprehensive literature research in Medline, Cochrane Central and Scopus databases, from conception until August 31th, 2021 and analyzed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Results: Database research retrieved 120 studies; sixteen met eligibility criteria, providing 1813 (1814 hips) evaluable patients. Acetabular erosion was significantly higher for unipolar group at 6 and 12 months (p = 0.02 and p = 0.01 respectively). Patients in the bipolar group presented significantly better hip function at 12 and 24 months (p = 0.02 and p = 0.04 respectively). Postoperative pain was significantly less in the bipolar group at 12, 24 and 48 months (p = 0.01). No statistically significant differences were found regarding the postoperative rates of deep infection, mortality, re-operation and dislocation.

Conclusion: This study showed that patients with dFNFs treated with bipolar hemiarthroplasty have lower acetabular erosion rates at 6 and 12 months postoperatively, better hip function at 12 and 24 months, better QoL and less pain, when compared with unipolar. No statistically significant difference could be established regarding deep infection, mortality, re-operation and dislocation rates.

Keywords: Bipolar hemiarthroplasty; Displaced femoral neck fracture; Elderly; Postoperative results; Unipolar hemiarthroplasty.