Periprosthetic Osteolysis after Total Ankle Arthroplasty

Background: Periprosthetic osteolysis in total ankle arthroplasty (TAA) is a substantial problem. We report the incidence and characteristics of periprosthetic osteolysis and its association with clinical outcomes after TAA using the HINTEGRA ankle system. Methods: Between May 2004 and April 2010, 126 primary TAA were performed on 115 patients. We excluded 27 ankles with a follow-up of less than 24 months; thus, 99 ankles in 90 patients with a mean follow-up of 40.8 (range, 24-89) months were included in the study. Pain and clinical outcomes were assessed using the visual analog scale and the American Orthopaedic Foot and Ankle Society score. Fluoroscopy was used for optimum visualization of the bone-implant interfaces on radiographs. Computed tomography (CT) was conducted on 25 ankles that exhibited progression of osteolysis. Results: Radiographs revealed that 37 of the 99 ankles showed radiologic evidence of osteolysis; of these, 10 demonstrated continuous progression over the study period. Helical CT scans were more accurate than radiographs for identifying and measuring periprosthetic osteolysis in TAA. None of the demographic parameters were substantially different between the 2 groups of subjects (with or without osteolysis). No major association was found between the presence of osteolysis and clinical and radiologic outcomes. Conclusion: Osteolysis associated with TAA may indeed be common in the postoperative period. Although most of the osteolytic lesions observed here were relatively quiescent, these lesions raise concerns in contemporary TAA because of their incidence rate and the potential for later mechanical failure as compared to arthrodesis. Early diagnosis and careful evaluation of osteolysis may provide a clinical opportunity for limited revision surgery in ankles of impending prosthesis failure.