Arthroscopic vs Open Ankle Arthrodesis: A 5-Year Comparison

Abstract

Category: Ankle; Ankle Arthritis; Arthroscopy Introduction/Purpose: End-stage ankle arthritis has long been managed surgically with open ankle arthrodesis (OAA). More recently, arthroscopic ankle arthrodesis (AAA) is thought to be associated with improved patient-reported outcome measures (PROMs) and fewer complications. The objective of this study was to systematically compare these two approaches in long-term PROMs, major complication rates and survivorship of the ankle fusion. Methods: In this retrospective longitudinal cohort study, all patients with an ankle fusion done at our institution and a minimum two-year follow-up were screened for inclusion. Patients demographics at baseline were collected including: age, gender, BMI, smoking status, diabetes status as well as preoperative ankle arthritis COFAS (Canadian Orthopedic Foot and Ankle Society) type. The following PROMs were completed preoperatively, at 6-months and annually thereafter to five years: AAS, AOS, SF-36, expectation, satisfaction and swelling scores. PROMs were compared at all timepoints using a mixed-effects regression model adjusted for baseline patients' demographics, COFAS type and PROMs. Major postoperative complications and survival analysis/rate of revision of the ankle fusions were also compared. Results: Of 874 patients screened for inclusion, 351 ankle fusions done between 2003 and 2019 were eligible for the study, 223 AAA and 128 OAA. The two groups were similar at baseline with respect to demographics, but COFAS type was higher in the OAA group and AAS and AOS scores were better in the AAA group. At one-year post-operatively, there was a higher mean AAS score in the AAA group, but there were no other differences in outcomes at any other timepoint. Survivorship of the ankle fusion in the arthroscopic group was lower (ie higher rate of revision) due to a higher rate of amputation or fusion. Deep infection and wound complications were more common with OAA and accounted for most ankle fusion revisions in this group. Conclusion: There were no consistent differences in PROMs of patients who underwent AAA versus OAA patients up to five- years postoperatively. Ankle fusions done arthroscopically had a lower survivorship rate compared to those done with the open approach due to a higher rate of major complications. Previously proposed advantages of AAA over OAA may therefore need to re-assessed and weighed against the technical challenges and associated complications of the arthroscopic technique.