Takedown of Painful Ankle Arthrodesis to Total Ankle Arthroplasty: A Case Series of 77 Patients.

Treatment of painful or malaligned ankle arthrodesis can present as a challenging issue. Several published studies have demonstrated that takedown of a painful ankle arthrodesis to total ankle arthroplasty can assist in restoring some sagittal plane motion and improving functional scores. The goal of this study was to contribute to the limited body of literature with the largest cohort and longest follow-up to date. A retrospective analysis was performed on patient and surgical characteristics of those who underwent a conversion of a painful ankle arthrodesis to a total ankle arthroplasty by 1 of 3 experienced total ankle arthroplasty surgeons from February 2003 to December 2016 with ≥2 years of follow up. Seventy-seven subjects were included for evaluation, with an implant retention rate of 88% (68 of 77) and mean follow-up of 8.3 years (range 2.6 to 15.8). Of the 11 (14%) failures (defined as retrieval or exchange of metallic components), 8 (10%) were revised to a total ankle replacement, 2 (2%) underwent revision arthrodesis, and 1 (1%) elected for below-the-knee amputation. The mean time since the primary arthrodesis was 8.6 years (range 1 to 44), and the longer time interval between primary arthrodesis to takedown total ankle arthroplasty did not correlate with poorer outcome scores or increased risk of failure. The mean American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot, Buechel-Pappas, and visual analog pain scale scores improved from preoperative values, with less satisfaction noted in those who needed revision surgery. The conversion of a painful ankle arthrodesis to a total ankle implant is a viable option to obtain range of motion and improved patient satisfaction scores similar to primary total ankle replacement.