Prospective Comparison of Ankle Replacement and Ankle Arthrodesis 4 Years After Surgery

Abstract

Category: Ankle; Ankle Arthritis Introduction/Purpose: The objective of this study was to compare physical and mental function, ankle-specific function, pain intensity, and rates of revision surgery and minor complications between ankle replacement and ankle arthrodesis in a prospective cohort study with minimum 4 year follow up after surgery. Methods: This prospective cohort study enrolled subjects from May 2012 to May 2015 included 517 subjects from 6 centers. Inclusion criteria ensured patients were suitable for both treatments while exclusion criteria were those with disabilities or diseases other than OA that effected ambulatory function including metabolic, neurologic, or musculoskeletal diseases such as hip or knee OA Outcomes were measured pre-treatment and 4-7 years after surgery. Linear mixed effects regression was used to determine if there were differences in postoperative improvement in each continuous outcome by surgical procedure. The primary outcomes included the Foot and Ankle Ability Measure (FAAM), and the FAAM sport, the Short Form-36 (SF-36) Physical and Mental Component Summary (PCS and MCS) scores, the Chronic Pain Grade (CPG) including average pain, worst pain and pain interference. Data were collected by study coordinators who were not involved in the surgery. Results: Of the 517 patients (414 receiving TAA, 103 receiving AA) with baseline assessment, 400 (325 TAA and 75 AA) were followed to 4 years. Pre-treatment, the two groups were not significantly different by sex, race, marital status, education, severity of OA. Data were adjusted, BMI, age. Patients demonstrated mean improvement in the FAAM and CPG outcomes at 1 year and maintained improvement out to 4 years (p<.001) regardless of surgery. TAA patients had significantly greater improvement in FAAM ADL score at all post-op visits compared to AA patients, with improvement at 4 year post-op 10 points greater (95% confidence interval 4, 17, p<.001). Similar differences in improvement occurred for the FAAM Sports and worst pain outcomes, although these differences were not statistically significant at all follow-ups. Conclusion: At 4 years post treatment, patients who were treated by ankle arthrodesis and ankle arthroplasty had sustained significant improvement. Patients treated with ankle replacement had greater improvement in FAAM and pain compared to those treated with arthrodesis. There was no difference in adverse events in the two groups