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

Background: We 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 and talar shoulder hemiarthroplasty for chronic medial osteochondral lesions of the talus.

Methods: Eleven patients underwent talus resurfacing and six patients had 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 (cumulative Foot and Ankle Outcome Score, from 41 to 42; Foot and Ankle Ability Measures for daily activities [FAAM-ADL], from 43 to 46; EQ-5D-3L time trade-off, from 0.38 to 0.39; Tegner activity scale score, from 1.6 to 2.0) but moderately after hemiarthroplasty (cumulative Foot and Ankle Outcome Score, from 58 to 68; FAAM-ADL, from 37 to 71; EQ-5D-3L time trade-off, from 0.53 to 0.72; Tegner activity scale score, from 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 2-year follow-up, without any radiographic osteoarthritis progression of the remaining joint. However, patient-reported ankle function, quality of life, and activity level showed a tendency toward only minor improvement after resurfacing but a moderate increase after hemiarthroplasty.