Differences in outcomes following total ankle replacement in patients with neutral alignment compared with tibiotalar joint malalignment.

Abstract

Excessive tibiotalar malalignment in the coronal plane has been considered by some to be a contraindication to total ankle replacement. The purpose of the present study was to compare clinical outcomes and physical performance measures according to preoperative tibiotalar alignment. One hundred and three patients undergoing total ankle replacement were grouped according to coronal plane tibiotalar alignment. Seventeen patients had an excessive deformity (>15° of varus or valgus), twenty-one had moderate valgus alignment (5° to 15° of valgus), twenty-seven had moderate varus alignment (5° to 15° of varus), and thirty-eight had neutral alignment (<5° of varus or valgus). Outcome measures, including the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, the Foot and Ankle Disability Index (FADI), the Short Form-36 (SF-36), the timed up and go test (TUG), the four square step test (4SST), and walking speed, were assessed preoperatively and at one and two years after total ankle replacement. Coronal plane alignment improved following the procedure, with 36.9% of patients having neutral alignment preoperatively as compared with 95% postoperatively. To achieve this alignment, adjunctive procedures, including deltoid ligament release, lateral ligament reconstruction, and posterior soft-tissue releases, were necessary. Significant improvements were seen for the Page: 3 AOFAS pain, function, alignment, and hindfoot scores (p < 0.001) and the SF-36 subscales of body pain, physical function, and role physical (p < 0.001) following total ankle replacement. Walking speed and the FADI, TUG, and 4SST scores also improved significantly (p < 0.001). Subgroup analysis demonstrated no significant differences in clinical outcomes and physical performance measures based on preoperative coronal plane alignment. Total ankle replacement improves clinical and functional outcomes independent of preoperative tibiotalar alignment when postoperative alignment is restored to neutral at the time of arthroplasty. Therapeutic level IV. See Instructions for Authors for a complete description of levels of evidence.