Non-union rates and complications after elective interphalangeal joint arthrodesis of the hand: a cohort study of 366 arthrodeses in 289 patients

BACKGROUND AND PURPOSE: Interphalangeal joint arthrodesis of the hand is a common procedure, but data on outcomes and complications is limited. We aimed to determine the non-union rate, evaluate risk factors for non-union, and investigate the frequency and distribution of complications across different fixation methods. METHODS: We retrospectively reviewed all interphalangeal joint arthrodeses performed between 2014 and 2022. Union and non-union were defined clinically and/or radiographically. Potential risk factors for non-union were evaluated by logistic regression with cluster-robust standard errors accounting for clustering of multiple arthrodeses within patients. RESULTS: After exclusions, 366 arthrodeses in 289 patients with ≥ 2 years of follow-up were analyzed. The median age was 63 years (interquartile range [IQR] 57-72) among women and 58 years (IQR 41-69) among men. Non-union occurred in 20 of 366 arthrodeses (5.5%, 95% confidence interval [CI] 3.6-8.3). Men had higher odds of non-union than women, but the difference was not statistically significant (OR 2.43, CI 0.98-6.01); no other characteristic was associated with non-union. Hardware-related complications were frequent, particularly following fixation with K-wires and cerclage, and resulted in hardware removal in 47% of cases. Other complications included superficial infections in 7% of cases, deep infections in 4%, and malunion in 4%. CONCLUSION: Elective interphalangeal joint arthrodesis was associated with a non-union rate of 5.5% (CI 3.6-8.3) and few major complications; however, hardware-related problems were frequent and commonly hardware removal was required.