Metallic hemiarthroplasty for the treatment of end stage hallux rigidus: mid-term implant survival, functional outcome and cost analysis

G. Dall, N. Clement, D. McDonald, I. Ahmed, A. Duckworth, H. Shalaby, J. McKinley

Introduction: We present a review of 97 consecutive BioPro^® metallic hemiarthroplasties performed in 80 patients for end-stage hallux rigidus, with a minimum of five years follow-up.

Results: The mean age of the cohort was 55 (22 to 74) years. No patient was lost to follow-up. There were 15 revisions performed, one for infection, two for osteolysis, and 12 for pain. The all cause survival rate at five years was 85.6% (95% confidence interval (CI) 83.5 to 87.9). Younger age was a significant predictor of revision (odds ratio 1.09, 95% CI 1.02 to 1.17, p=0.014) on excluding infection and adjusting for confounding variables (Cox regression). Significant improvements were demonstrated at 5 years in the Manchester Oxford foot questionnaire (13.9, 95% CI 10.5 to 17.2) and in the physical component of the short form 12 score (6.5, 95% CI 4.1 to 8.9). The overall satisfaction rate was 72%. The cost per quality-adjusted-life-year at 5 years, accounting for a 3% per year revision rate, was £3,714.

Conclusion: The BioPro offers good short to mid-term functional outcome and is a cost effective intervention. The relative high revision rate is associated with younger age and the use of this implant may be limited to older patients.