THE AGILITY TOTAL ANKLE REPLACEMENT: A CRITICAL LOOK AT EARLY EXPERIENCE

Abstract

From October 1999 to April 2003, 123 patients (127 ankles) underwent an Agility total ankle replacement. Prospective data were collected preoperatively, at 6 and 12 months after surgery, and thereafter annually, and included the AOFAS Ankle and Hindfoot Scale (AHS), Musculoskeletal Functional Assessment Injury and Arthritis Survey (MFA), Visual Analogue Pain Scale, patient satisfaction and standardised radiographs.

Fifty-six percent of the operations were performed for post-traumatic degenerative joint disease, 41% for primary degenerative joint disease, 1% for rheumatoid arthritis and 2% for avascular necrosis. At least one previous surgical procedure had been performed on 62% of ankles. In 6% there were intra/perioperative complications, including seven wound problems (one major, six minor), five lateral fractures, one medial malleolus fracture, one bone stock deficiency, one tibial nerve injury, one ankle in varus and one flap necrosis. Late complications included eight syndesmosis nonunions that needed bone grafting, one infection that led to a fusion, one unrelated talar fracture that led to a fusion, and one component subsidence that was revised. There were two patients with progressive varus and two with progressive valgus deformities. One patient underwent a below-knee amputation for chronic infection. Most of the perioperative complications occurred in the first 40 patients. The preoperative AHS of 43 (4 to 70) increased six months postoperatively to 75.45 and to 85 at two years. Patient satisfaction preoperatively was 0.92 out of 5 and 4.2 at two years. Baseline MFA values indicative of severe dysfunction (9.26) showed marked improvement in all parameters at two-year follow-up (21.83).

The Agility ankle replacement procedure is technically demanding and there are pitfalls and complications. The early results are promising, but follow-up has not been long enough to permit an objective opinion.