Scandinavian total ankle replacement: a 3.7-year average followup of 65 patients

The purpose of the current prospective study was to determine the midterm results of 68 total ankle replacements with the Scandinavian Total Ankle Replacement (S.T.A.R.) prosthesis. The 65 patients (34 women and 31 men; mean age at surgery, 56.1 years [range, 22-85 years]) were assessed clinically and radiologically after 3.7 years (range, 2.4-6.2 years). Thirty-five patients (54%) were totally pain-free. The overall clinical score was graded as excellent or good in 67 ankles. The American Orthopaedic Foot and Ankle Society hindfoot score improved from 24.7 points (range, 3-44 points) preoperatively to 84.3 points (range, 44-100 points) at followup. Three patients (three ankles, 4.4%) had a ballooning bone lysis on the tibial side. Despite prophylaxis, periarticular hypertrophic bone formation was seen in 43 ankles (63%; 42 patients), associated with a decrease of dorsiflexion and plantar flexion. Nine ankles (13%; nine patients) had revision surgery because of problems with the components and 14 ankles (21%; 14 patients) had secondary or additional operations. All revision or secondary surgeries were successful, and no ankle had to be converted to an ankle arthrodesis. The early experience with the S.T.A.R. ankle implant is encouraging, although we have encountered more complications and potential problems than previously reported.