SLR - January 2020 - Emily E. Zulauf
Reference: Demetracopoulos CA, Cody EA, Adams SB, DeOrio JK, Nunley JA, Easley ME. Outcomes of Total Ankle Arthroplasty in Moderate and Severe Valgus Deformity. Foot & Ankle Specialist. 2019 June; 12(3):238–245.Scientific Literature Review
Reviewed By: Emily E. Zulauf, DPM
Residency Program: Grant Medical Center – Columbus, OH
Podiatric Relevance: Total ankle arthroplasty (TAA) is increasingly utilized as treatment for end-stage ankle arthritis over the gold standard ankle arthrodesis. Contraindications for TAA traditionally included coronal plane deformity over 15 degrees; however, advances in implant technology and improved surgical techniques have allowed for utilization of TAA in severe deformity correction. Recent studies report promising results in this patient population. The present study retrospectively reviewed 80 patients with valgus deformity greater than or equal to 10 degrees receiving TAA. Prospective patient outcomes were reported and clinical and radiographic outcomes were assessed.
Methods: A level IV retrospective review of 80 patients with valgus deformity greater than or equal to 10 degrees receiving TAA was performed. Moderate deformity (55 patients) was defined as a tibiotalar angle of at least 10 degrees but less than 20 degrees of valgus. Severe deformity (25 patients) was defined as a tibiotalar angle of at least 20 degrees of valgus. Three total ankle prostheses were utilized and included both fixed and mobile bearing implants. Functional outcomes were assessed with Visual Analog Scale for pain (VAS), Short-Form 36 (SF-36), Foot and Ankle Disability Index (FADD), Short Musculoskeletal Function Assessment (SMFA), and the American Orthopaedic Foot and Ankle Society (AOFAS) Hindfoot Score). Radiographic assessment included preoperative valgus deformity and postoperative deformity correction. Secondary outcomes reported included complications, reoperations and revisions.
Results: A significant improvement was reported in VAS pain, SF-36, SMFA Function, SMFA Bother, and AOFAS Hindfoot scores postoperatively. Tibiotalar angle improved from a mean of 15.5 degrees preoperatively to 1.2 post-operatively in both groups. Long-term maintenance of deformity correction was reflected in comparison of one-year and final follow up measurements—final tibiotalar angle did not differ between the two groups. One wound complication was reported in each of the moderate and severe deformity groups. There was no difference in reoperation or revision rates between the two groups.
Conclusions: Thanks to newer generation implants, TAA may be performed safely in patients with severe coronal plane deformity without increased risk of failure. Correction was achieved and maintained in patients with moderate and severe valgus deformity. This study reported significant improvement in all patient-reported outcome scores for patients with moderate and severe valgus deformity. Noted limitations include its retrospective nature, short follow-up period and no control on patient-specific factors affecting outcomes after TAA. Indications for TAA have evolved and should not exclude patients with advanced deformity.