Radiological and Clinical Evaluation of Acetabular Erosion in Bipolar Hemiarthroplasty for Femoral Neck Fractures: Long-Term Outcomes and Predictive Factor

Abstract

Introduction: Bipolar hemiarthroplasty is widely used for femoral neck fractures in elderly patients due to its reduced surgical risk and initial reduction in acetabular wear. However, long-term studies reveal that acetabular erosion remains a concern, particularly in younger, more active patients. This study evaluates the incidence and progression of acetabular erosion over time and examines the influence of patient demographics and activity levels on functional outcomes post-hemiarthroplasty.

Materials and Methods: This retrospective observational study included 77 patients who underwent bipolar hemiarthroplasty for femoral neck fractures, with a minimum follow-up of two years. Radiographic assessments categorized acetabular erosion into four grades, while functional outcomes were measured using the modified UCLA activity score. Statistical analysis was conducted to assess correlations between erosion severity, follow-up duration, age, and activity level.

Results: Acetabular erosion increased with follow-up duration, with 45.5% of patients showing moderate to severe erosion at four or more years post-surgery. Higher erosion grades correlated with lower UCLA scores, indicating diminished functionality. Younger, more active patients experienced faster erosion rates, whereas older, less active patients had milder erosion.

Conclusion: Bipolar hemiarthroplasty remains suitable for elderly, low-activity patients, but younger, active patients may benefit from total hip arthroplasty to avoid accelerated acetabular erosion. Individualized treatment planning and regular follow-up are essential to monitor and manage acetabular wear over time.