2021 Roger A. Mann Award Winner: Long-Term Revision Rates and Functional Outcomes of Total Ankle Arthroplasty and Ankle Arthrodesis

Abstract

Category: Ankle Arthritis; Ankle Introduction/Purpose: Recent studies have shown acceptable long-term survival rates with TAA however there remains a general paucity of information directly comparing ankle arthroplasty to arthrodesis over long-term follow-up. This study compares revision rates and functional outcomes for a large cohort of patients undergoing ankle arthrodesis or arthroplasty. All surgeries were performed by a single surgeon from 1999 to 2013. Ankle arthrodesis was performed using a standardized 3-screw technique with anterior plate supplementation. Arthroplasty was performed utilizing the Scandinavian Total Ankle Replacement (STAR) prosthesis. Methods: A retrospective chart review was performed for 335 consecutive cases in 326 patients (198 ankles in the arthrodesis group and 137 in the arthroplasty group). Patient demographics including age, sex, body mass index (BMI), and preoperative diagnoses were collected. Foot Function Index (FFI) scores were obtained and recorded at final outpatient follow-up. Primary outcomes included the rate of revision surgery and functional outcome scores. Secondary outcomes included perioperative complications such as polyethylene fracture and patients who went on to undergo postoperative subtalar fusion for symptomatic adjacent joint arthritis. Results: Ten (6%) ankles in the arthrodesis group and twenty-one (15%) in the arthroplasty group required revision surgery at a mean of 8.9 +- 6.5 and 61.1 +- 52.9 months, respectively [P=.039]. One hundred four of the 335 cases were available to complete functional outcome surveys at final follow-up at a mean of 11.2 +- 4.1 years from time of surgery (minimum 6-year follow-up). Mean FFI scores were significantly better in the arthroplasty group (40.3 +- 36.9) than in the arthrodesis group (61.5 +- 45.1) [P=.011]. Thirteen polyethylene components in 12 TAAs (8.7%) required replacement for fracture at an average of 9.6 +- 4.2 years postoperatively. Seven (3.5%) cases in the arthrodesis group and three (2.2%) in the arthroplasty group went on to undergo subtalar fusion at an average of 4.9 +- 3.9 years post-operation [P=.536]. Conclusion: Long-term functional outcome scores were better in TAA patients; however, the revision rate for major complications was found to be greater over time. While the ankle arthroplasty group did show a slightly lower frequency of adjacent joint arthritis progression leading to subsequent subtalar fusion, this difference was not statistically significant. To our knowledge, this is the largest and longest-term follow-up comparing the STAR prosthesis to ankle arthrodesis published in the United States to date.