Outcomes of Total Ankle Arthroplasty in Ankles with >20° of Coronal Plane Deformity

Background: A preoperative severe coronal plane deformity of >20 degrees has been considered a contraindication for total ankle arthroplasty. We aimed to evaluate whether outcomes of total ankle arthroplasty in ankles with severe coronal plane deformity (20 degrees to 35 degrees of varus orvalgus) are comparable with those with moderate deformity (5 degrees to 15 degrees of varus orvalgus). Methods: A total of 148 consecutive ankles (142 patients) that underwent primary total ankle arthroplasty using the HINTEGRA prosthesis were included. The overall mean follow-up duration was 74 months (range, 24 to 160 months). We divided all patients into 2 groups according to the preoperative coronal plane tibiotalar angle: the severe group (36 patients, 41 ankles) and the moderate group (106 patients, 107 ankles). Clinical and radiographic outcomes were analyzed for intergroup differences, and multivariable regression was used to adjust for baseline characteristics. Patients in each group showed similar characteristics in mean age, sex, mean body mass index, and median follow-up duration. Results: At a mean follow-up of 74 months, we found no significant intergroup difference in the Ankle Osteoarthritis Scale pain and disability score, American Orthopaedic Foot & Ankle Society ankle-hindfoot score, Short Form-36 Physical Component Summary score, visual analog scale pain score, or ankle range of motion (p > 0.05). However, the final tibiotalar angle, talar tilt angle, and number of outliers were greater in the severe group (p < 0.05). Complication rates did not show a significant difference between the 2 groups (p > 0.05). The overall survival probability of the implant was 91.3% (92.3% in the severe group and 90.7% in the moderate group) (p = 0.354). Conclusions: Total ankle arthroplasty in ankles with preoperative severe coronal plane deformity showed satisfactory and comparable clinical outcomes without increasing complication rates relative to those with moderate deformity in the intermediate-term follow-up. Our results suggested that total ankle arthroplasty may be considered in ankles with deformity of >20 degrees.