Long-term outcome of ankle replacements in patients with inflammatory joint disease and osteoarthritis: Is there a difference?

H. Majeed, J. Davenport, M. Karski, R. Smith, T. Clough

Aims: We aim to provide long-term implant survival rates of total ankle replacement in patients with inflammatory joint disease and osteoarthritis.

Methods: Between November 1993 and February 2000, a single surgeon implanted 200 Scandinavian Total Ankle Replacement (STAR) prostheses (184 patients). Data were collected prospectively. Pain and function were assessed using American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scoring system. Failure was considered as re-operation with revision of one or all the components or conversion to arthrodesis.

Results: The underlying diagnosis was inflammatory joint disease in 119 and primary or posttraumatic osteoarthritis (OA) in 81 ankles. Mean age at implantation was 60 years with a significant difference in the two groups (IJD=58.2 years, OA= 62.6 years, p= 0.01). Mean follow-up was 15.8 years. Mean AOFAS scores were comparable in the two groups (IJD=61, OA=60). Nineteen patients were lost to follow up. In total 32 ankles required revision (16%); 14 in IJD (11.7%) and 18 in OA group (22.2%), significantly lower in IJD group (p=0.03). Average time from surgery to implant failure was 9.5 years in patients with IJD and 7.1 years in patients with OA. One hundred patients (113 ankles) died during the observation period, of which 87 patients (100 ankles) died without requiring revision surgery. Among the surviving 84 patients (87 ankles, IJD=40, OA=47), seven ankles in patients with IJD and twelve ankles in patients with OA required revision surgery. At 15.8 years, the overall implant survival was 76.16%. The implant survival was 81.95% in patients with IJD and 68.10% in patients with OA (p=0.03).

Conclusion: We report significantly better long-term implant survival rates in patients with inflammatory joint disease compared to OA after total ankle replacement with similar functional results. The predominant mode of failure was coronal plane malalignment in IJD and aseptic loosening in OA.