Risk Factors for Reoperation After First Metatarsophalangeal Arthrodesis: A Retrospective Case-Control Study

BACKGROUND: Arthrodesis of the first metatarsophalangeal joint (MTPJ) is one of the most common procedures in foot and ankle surgery. The aim of our study was to explore potential patient-related, radiologic, and surgery-related risk factors for reoperation after first MTPJ arthrodesis. METHODS: All first MTPJ arthrodesis operations between 2010 and 2020 in Helsinki University Hospital were retrospectively reviewed for patient-related risk factors for reoperation. For radiologic and surgery-related risk factors, all reoperated and a propensity-matched cohort of non-reoperated cases were assessed. RESULTS: A total of 3911 primary operations and 453 reoperations with a mean follow-up of 9.3 years (SD, 2.9; range, 3.8-14.5 years) were assessed. Reoperation rate was 11.6%. Preoperative radiologic grade I arthrosis according to the Coughlin and Shurnas classification (OR 3.81, 95% CI 1.54-9.43) and a greater preoperative hallux valgus angle (OR 1.05, 95% CI 1.01-1.08) were both associated with an increased risk of reoperation. Factors associated with decreased risk for reoperations were using snap-off screws as a fixation method (OR 0.31, 95% CI 0.10-0.91), female sex (OR 0.78, 95% CI 0.61-0.99), age (OR 0.97, 95% CI 0.96-0.98), and greater change in hallux valgus angle (OR 0.95, 95% CI 0.92-0.98). CONCLUSION: Several patient-related, radiologic, and surgery-related risk factors were associated with increased or decreased risk for reoperation. Our findings identify potential predictors of reoperation; however, causality cannot be inferred because of the retrospective design.