Does Preparation of the Subtalar Joint for Primary Union Affect Clinical Outcome in Patients Undergoing Intramedullary Nail for Rheumatoid Arthritis of the Hindfoot and Ankle?

This study aimed to evaluate whether preparation of the subtalar joint affects the clinical outcomes after tibiotalocalcaneal arthrodesis using an intramedullary nail with fins for rheumatoid ankle/hindfoot deformity. Fifty-three joints in 51 patients who underwent tibiotalocalcaneal arthrodesis using an intramedullary nail with fins for rheumatoid arthritis at 2 institutions were included. Ten patients were male and 41 were female, with a mean age at surgery and follow-up period of 61.3 years and 71.6 months, respectively. Radiographic bone union was evaluated at the most recent visit. Univariate and multivariable analyses were performed to determine the risk factors associated with nonunion. The mean postoperative Japanese Society for Surgery of the Foot ankle/hindfoot scale was 65.3 (range, 5-84). The tibiotalar nonunion rate was 0%, whereas the subtalar nonunion rate was 43.3% (23 joints). Revision surgery was performed in 5, all of which were due to painful subtalar nonunion. Absence of subtalar curettage and earlier postoperative weightbearing were significantly associated with subtalar nonunion (p = .0451 and p = .0438, respectively). Subtalar nonunion after tibiotalocalcaneal arthrodesis for rheumatoid hindfoot is associated with higher revision rate. To decrease the risk of subtalar nonunion after tibiotalocalcaneal arthrodesis with an intramedullary nail in rheumatoid patients, curettage for the subtalar joint should be performed, and full weightbearing should be delayed until at least 26 days postoperatively.