Short-term Results of the Agility Total Ankle Arthroplasty

Abstract

Purpose: Recently, there has been increasing interest in total ankle arthroplasty as an alternative to ankle arthrodesis. This study examined the short-term results of total ankle arthroplasty using an Agility prosthesis. Materials and Methods: This study reviewed the results of 11 patients who underwent total ankle arthroplasty using the Agility prosthesis between May, 2003 and May, 2004. With a postoperative follow-up period of 2 years, 10 patients (10 ankles) were available for review at the time of the follow-up. The clinical evaluation included the ankle range of motion, the personal type of preferred shoe, walking pain (VAS score) and the American Orthopaedic Foot and Ankle Society (AOFAS) ankle score. In addition, the patients were asked whether they were satisfied with the outcome and if they would choose to undergo the same procedure again. The radiologic evaluation included the loosening of the prosthesis, osteolysis and syndesmosis union. The anterior surgical approach was used. The syndesmosis area was fixed using 2 cannulated screws inserted percutaneously in 9 cases and a plate in 1 case. Results: The patients consisted of two men and eight women. The average age was 51.8 years (range 41 to 67) with an average follow-up of 30.3 (range 24 to 36) months. The mean preoperative and postoperative AOFAS ankle scores were 38.2 and 73.8, respectively, demonstrating significant improvement. The mean preoperative and final follow-up walking pain was 8.9 and 2.8, respectively. The ankle range of motion was decreased slightly at the final follow-up. Five patients required a cane to walk. Radiographic analysis showed no prosthesis failure, even though osteolysis occurred around the prosthesis in all cases. Only one case showed further progression. Union in the syndesmosis area occurred within 6 months in 5 cases and delayed union was observed in 3 cases, and nonunion was observed in 2 cases. Sensory loss in the area innervated by the deep peroneal nerve and a fracture in the lateral malleolus was encountered in one case, but this recovered with conservative treatment. Subtalar joint arthritis was noted in one case. Conclusion: Agility total ankle arthroplasty results in a favorable outcome at the short-term follow-up. However, total ankle arthroplasty is associated with radiographic complications including syndesmosis nonunion and osteolysis. Only syndesmosis nonunion was associated with the clinical results. Therefore, long-term follow-up is considered to be necessary to demonstrate osteolysis and loosening with their clinical association.