Radiographic Outcomes of Mobile-Bearing Total Ankle Arthroplasty for Patients With Rheumatoid Arthritis

Background: Ankle disorders in patients with rheumatoid arthritis (RA) reduce their quality of life and activities of daily living. The aim of this study was to evaluate the midterm clinical and radiographic outcomes of TAA in patients with RA. Methods: This retrospective study included patients with a minimum follow-up of 2 years. A total of 37 RA patients (39 ankles) were enrolled in this study from August 2006 to March 2016. All the patients had undergone primary cemented mobile-bearing total ankle arthroplasty (TAA). Nine ankles received arthrodesis of the subtalar joint simultaneously. Patient-reported outcomes were measured preoperatively and at the latest follow-up by Self-Administered Foot-Evaluation Questionnaire (SAFE-Q). Radiographs of the ankle were analyzed preoperatively and at all follow-up visits to measure the periprosthetic radiolucent line, migration of the tibial component, and the subsidence of the talar component. Intraoperative and postoperative complications were recorded. The average duration of follow-up for the entire cohort was 5.0 +/- 2.0 years (range 2.1-10.1 years). Results: All subscales of the SAFE-Q had improved significantly at the latest follow-up. No significant difference was found between the range of motion of the ankle before and after the surgery. Radiolucent lines were observed in 28 (73.7%) ankles. Migration of the tibial component and subsidence of the talar component were found in 8 (21.1%) and 11 (28.9%) ankles, respectively. Intraoperative malleolus fractures occurred in 3 (7.7%) ankles and delayed wound healing in 10 (25.6%) ankles. Four ankles were removed because of deep infection or noninfective loosening, resulting in an implant survival rate of 88.4% (95% CI, 0.76-1.0) at 10 years. Conclusion: The midterm patient-reported outcomes and implant retention rate after cemented mobile-bearing TAA for RA patients were satisfactory. However, a low radiographic implant success rate was observed.