Ankle arthrodesis and replacement are the widely accepted options in managing end-stage ankle arthritis. Ankle replacement as an alternate treatment option for ankle arthritis is relatively new and this is in large part to the successes observed with hip and knee arthroplasty for arthritis. Relative benefits of ankle replacement and arthrodesis remains a contentious topic. We conducted a multicenter pilot randomized controlled trial, first of its kind, comparing the clinical outcomes of ankle arthrodesis and ankle replacement in managing ankle arthritis. We hypothesized that clinical outcomes would be similar for both.

Patients recruited for this study were part of Canadian Orthopaedic Foot and Ankle Society (COFAS) Database. Canadian orthopaedic surgeons with fellowship training in foot and ankle surgery or extensive experience in the surgical treatment of end stage ankle arthritis determined whether the patient met the criteria for randomization, skeletal maturity, symptomatic ankle arthritis no longer amenable to non-operative management, and ability to give informed consent. Data was collected on patient demographics, follow-up time period, complication rates, and Ankle Osteoarthritis Scale (AOS) and Short Form-36 (SF-36) scores. Our analysis of clinical outcomes was divided into two parts: (1) comparison of pre and postoperative data for each cohort separately, and (2) comparison of outcome scores, and revision rates between both cohorts. We employed the Student's t-test and calculated effect sizes in assessing improvements in AOS and SF-36 scores from baseline to latest follow-up within and between the two groups. We also examined postoperative complication and reoperation rates in the study population using the standardized coding system for reoperations following ankle replacement and arthrodesis.

Thirty-nine ankles were enrolled in the study with a mean follow-up of 5.1 ± 2.8 years. Ankle osteoarthritis scale scores improved significantly from baseline and last follow-up in both groups. The average baseline AOS total score for ankle replacement improved from 59.4 ±15.9 to 38 ±20 at last follow-up (p-value 19.7 to 31.8 ±16.5 at last follow-up (p-value 25.4 compared to ankle replacement's 20.3 ±23. Two major complications (10.5%) were observed in the ankle replacement cohort while the ankle arthrodesis cohort saw four major complications (20%).

Clinical outcomes of ankle replacement and arthrodesis were comparable. The ankle arthrodesis cohort held a slight advantage over ankle replacement in improvement of AOS scores, though not statistically significant. Rates of major complications and reoperations were higher with ankle arthrodesis.