Partial Ankle Arthroplasty: Talus Resurfacing for Mild-to-Moderate Osteoarthritis and Talus Hemiarthroplasty for Complex Osteochondral Lesions

Abstract

Background: To present prospective short-term results of a limited patient series treated with two innovative partial ankle arthroplasties: talar dome resurfacing for mild-to-moderate ankle osteoarthritis (OA) and talar shoulder hemiarthroplasty for chronic medial osteochondral lesions of the talus (OLT). Methods: Eleven subjects underwent talus resurfacing, and six subjects were enrolled for talar hemiarthroplasty. The outcome was followed by patient-reported measures and by pursuing serious adverse events or implant failures over a 2-year period. Progression of ankle osteoarthritis, peri-implant bone changes, and implant migration were followed radiographically. Results: Active dorsiflexion increased from 3° to 10° in resurfacing and from 15° to 22° in hemiarthroplasty. Patient-reported ankle function, quality of life, and activity level tended to improve only slightly after resurfacing (FAOS cumulative = 41 to 42; FAAM-ADL = 43 to 46; EQ-5D 3L = 0.38 to 0.39, Tegner activity scale = 1.6 to 2.0), but moderately after hemiarthroplasty (FAOS cumulative = 58 to 68, FAAM-ADL = 37 to 71, EQ-5D 3L = 0.53 to 0.72, Tegner activity scale = 3.1 to 3.1). No implant-related radiographic changes, implant failures, or implant-related revision surgeries were recorded. Conclusions: Based on a small and heterogeneous prospective case series, both partial ankle implants investigated were safe and stable over a 2-year follow-up period, without any radiographic OA progression of the remaining joint. However, patient-reported ankle function, quality of life, and activity level showed a tendency of only minor improvement after resurfacing but a moderate increase after hemiarthroplasty.