Outcomes of Total Ankle Arthroplasty in Rheumatoid Arthritis and Osteoarthritis: A Propensity Score-Matched Cohort Study.

BACKGROUND

Total ankle arthroplasty (TAA) is increasingly used as an alternative to ankle arthrodesis for patients with rheumatoid arthritis (RA), although its outcomes remain controversial. Using propensity score matching, this study compared clinical and radiographic outcomes of TAA for patients with RA and osteoarthritis (OA).

METHODS

Eighteen patients with RA were selected from 21 eligible cases and matched-using propensity score matching based on 8 baseline variables-to 36 patients with OA from a pool of 386. All patients underwent mobile-bearing TAA and were followed up for a minimum of 2 years. Clinical outcomes were assessed using the Ankle Osteoarthritis Scale, American Orthopaedic Foot and Ankle Society ankle-hindfoot score, Short Form-36 Physical Component Summary, and a visual analog scale for pain. Radiographic outcomes and postoperative complications were also evaluated.

RESULTS

At a mean follow-up of 7 years, both groups demonstrated improvement in all clinical outcome measures, with no significant differences between the RA and OA groups (p > 0.05). Radiographic outcomes, including postoperative tibiotalar angle, talar tilt angle, as well as the incidence values for periprosthetic osteolysis, implant subsidence, and aseptic loosening, were similar between groups. However, periprosthetic medial malleolar fractures occurred only in the RA group (3 cases, 16.7%; p = 0.033), and 2 cases of incision wound dehiscence were also observed in the RA group. No deep infections were reported in either group. Overall, reoperation rates did not differ significantly between groups.

CONCLUSIONS

Patients with RA who underwent TAA achieved clinical and radiographic outcomes comparable to those with OA. However, periprosthetic fractures and wound complications were more common in the RA group. Further studies with larger, matched cohorts and longer follow-up are needed to confirm these findings.