Union rates in hallux interphalangeal joint arthrodesis: A retrospective review of a reproducible surgical technique

Objective: To assess the radiographic union rate and complications following hallux interphalangeal joint arthrodesis (HIPJA) using a single reproducible surgical technique and report on possible technique tips to improve the union rate. Methods: A retrospective review of all HIPJAs performed by four foot and ankle orthopedic surgeons was conducted. The surgical technique, patient factors, indications, reoperation rate, complications, and radiographic evidence of arthrodesis were collected. Radiographic union was defined as two cortical continuations or trabecular bridging, absence of hardware failure, and the absence of lytic gapping at the arthrodesis site. Results: Thirty-five primary HIPJA procedures were identified with radiographic follow-up until union or non-union was confirmed. Our cohort demonstrated a 97.1% radiographic union rate with a mean time to union of 20 weeks. There were three reoperations: two cases (5.7%; 95% CI, 0.7%-19.2%) for removal of painful hardware and one case (2.9%; 95% CI, 0.07%-14.9%) for revision of a symptomatic non-union. Because only one non-union occurred, the study was not powered to identify independent predictors of non union. Conclusion: This cohort showed a mean above-radiographic union rate with a consistent surgical technique, meticulous joint preparation, and a single large intramedullary differential pitch screw for fixation. Radiographic union took longer than expected, with a mean of 20 weeks.