Severe Ankle Deformity Correction Following Transfibular Total Ankle Arthroplasty: A Comparative Cohort Analysis With Minimum 5-Year Follow-Up.

BACKGROUND

There are limited results about total ankle arthroplasty (TAA) in the setting of severe malalignment. The aim of this study was to compare midterm patient-reported and radiographic outcomes in patients with severe varus or valgus tibiotalar deformity treated with primary transfibular TAA at a minimum of 5-year follow-up.

METHODS

Retrospective review was performed of all primary transfibular TAA by a single surgeon from October 2012 to January 2020 and grouped based on preoperative coronal talar tilt angle. Severe preoperative deformity included cases with ≥10° of varus (n = 36) or valgus (n = 33), while cases within 5° of neutral coronal alignment (n = 140) served as a control group. PROMs included 12-item Short-Form Health Survey physical and mental component scores, Ankle Osteoarthritis Scale, and Visual Analog Scale. Alignment and periprosthetic cysts (>2 mm) were assessed on postoperative radiographs. Adverse events and reoperations were reported using the Canadian Orthopaedic Foot and Ankle Society Reoperation Coding System.

RESULTS

Aside from age (Neutral vs. Valgus, 58.1 vs. 64.2 years; p = 0.01), there were no significant differences in demographics, preoperative, or postoperative PROMs among the 3 groups. The median preoperative talar tilt was -15.1° (interquartile range [IQR], -17.8° to -13.1°) in the Varus and 16.0° (IQR, 12.0° to 19.5°) in the Valgus groups; there were no significant differences in median tibiotalar alignment between the 3 groups postoperatively. In the Neutral group, 1 patient had postoperative varus, and 2 patients had postoperative valgus deformity. In the Varus group, 1 patient had recurrent varus, and 1 patient progressed to valgus. Seven ankles had periprosthetic cysts. Overall reoperation rates were similar (Neutral, 34%; Varus, 33%; Valgus, 36%) with no implant revisions.

CONCLUSION

Transfibular TAA is capable of correcting severe coronal tibiotalar malalignment in the primary treatment of end-stage ankle arthritis. Patients with ≥10° varus or valgus deformity demonstrated postoperative patient-reported and radiographic outcomes similar to those with neutral ankle alignment at midterm follow-up, without an increased risk of reoperations.

LEVEL OF EVIDENCE: Level III. See Instructions for Authors for a complete description of levels of evidence.