BackgroundThe influence of pre-existing radiographic osteoarthritis on the functional outcome of elderly patientents with displaced intracapsular fractures of the femoral neck treated by hemiarthroplasty is unclear.MethodsWe prospectively examined the impact of pre-existing osteoarthritis on the functional outcome of 126 elderly patients with displaced intracapsular fracture of the femoral neck treated by hemiarthroplasty.ResultsThe mean age of the cohort was 82.7 years. At 12 months, we observed no statistically significant differences in the Harris hip score (p = 0.545), the timed up and go test (p = 0.298), the Tinetti test (p = 0.381) or the Barthel Index (p = 0.094) between patients with Kellgren and Lawrence grades 3 or 4 osteoarthritis, and patients with grades 0 to 2 changes. Furthermore, there were no differences in complication or revision rates.ConclusionsOur findings challenge the hypothesis that pre-existing osteoarthritis is a contraindication to hemiarthroplasty in elderly patients with femoral neck fracture.