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

Abstract

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). 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. 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. 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.