Should We Use Bipolar Hemiarthroplasty in Patients ≥70 Years Old With a Femoral Neck Fracture? A Review of Literature and Meta-Analysis of Randomized Controlled Trials.

Background: Bipolar (BHA) and unipolar hemiarthroplasties (UHA) are interchangeably used in elderly patients with a displaced femoral neck fracture. We ask if there is a difference between BHA and UHA with regards to hip function, in elderly patients.

Methods: Systematic review and meta-analysis was conducted of randomized controlled trials comparing BHA to UHA. The primary outcome was postoperative hip function scores. Secondary outcomes were overall health-related quality of life patient-reported outcomes, acetabular erosion, and postoperative complications. Data sources, last searched on June 1, 2020, were MEDLINE, EMBASE, Cochrane Library, and Web of Science.

Results: Fourteen randomized controlled trials were eligible for meta-analysis. There was no difference in hip function scores between BHA and UHA (standardized mean difference 0.32, 95% confidence interval [CI] -0.06 to 0.71, n = 1084, I = 87%). Patients with BHA with more than 2-year follow-up had better hip function scores (standardized mean difference 0.68, 95% CI 0.18-1.18, n = 700, I = 87%). There was no difference in European Quality of life- five dimensions scores with BHA (mean difference 0.08, 95% CI -0.01 to 0.17, n = 967, I = 82%). The use of BHA decreased the risk of acetabular erosion (relative risk 0.38, 95% CI 0.17-0.83, n = 1239, I = 0%). There was no difference for revision, mortality, infection, and dislocation (I = 0%).

Conclusion: There seems to be no difference between BHA and UHA with regards to hip function at 2 years. BHA might decrease the risk of acetabular erosion. There is a need for a large randomized controlled trial with a follow-up >2 years and better measurement tools to assess clinical benefits.

Level Of Evidence: II.