Session IX - Foot & Ankle

Anatomic Compression Arthrodesis Technique (ACAT) for Post-Traumatic Arthrosis of the Ankle: Results of Treatment

Steven D. Steinlauf, MD; Keith Heir, MD; Arthur Walling, MD; Roy Sanders, MD, Florida Orthopaedic Institute, Tampa, FL

Purpose: Ankle arthrodesis is the standard in surgical treatment of post-traumatic arthrosis. Many techniques exist, with the implication that no one technique is optimal. The purpose of this paper is to describe the results using an easily reproducible technique for arthrodesis of the ankle.

Methods: A retrospective review was performed of all patients who underwent ankle arthrodesis at our institution between 1986 and 1998. Our surgical technique employs joint debridement, drilling of the subchondral bone, deformity correction, and bone grafting. Ankle anatomy is maintained. Internal compression is achieved using large, cannulated lag screws. When necessary, a low profile anterior plate is applied. Follow-up radiographs were used to determine time to fusion and progression of arthrosis. Patients were evaluated with the AOFAS ankle and hindfoot score.

Results: Seventy-eight arthrodeses were performed in 76 patients. Adequate radiographic follow-up to confirm fusion was possible for 72 ankles (92%). Fusion occurred in 69 of 72 ankles (96%). Time to fusion averaged 15 weeks. Three nonunions occurred. After revision using the same technique, 2 of 3 nonunions fused. Thus, 71 of 72 ankles (99%) were successfully fused.

Two-year follow-up was possible for 61 ankles in 59 patients (78%). The average age was 51 years, (range 20-77 years). Twenty-three patients were involved in worker's compensation claims. Follow-up averaged 58 months, (range 24-150 months).

For patients not involved in a worker's compensation claim, the postoperative AOFAS ankle-hindfoot score averaged 72 points (range 28-96). Thirty-three of 35 patients (94%) were satisfied, 34 of 35 (97%) admitted to less pain, and 31 of 35 (89%) felt that their function had increased.

For those patients with a work-related injury, the average score was 66 points, (range 33-98). Sixteen of 19 (84%) were satisfied, 14 of 19 (74%) admitted to less pain, and 15 of 19 (79%) felt that their function had increased.

Complications involving the ankle occurred in 17 patients. These included 3 nonunions, 3 superficial infections, 8 suboptimal positions, 2 cases of tendinitis, and 1 case each of reflex sympathetic dystrophy and symptomatic leg length discrepancy. Three patients experienced complications related to the iliac crest bone graft donor site. In addition, 11 patients complained of painful hardware. Progressive arthrosis occurred at the subtalar joint in 58% of ankles, at the talonavicular joint in 50%, and at the calcaneocuboid joint in 8%.

Discussion: The Anatomic Compression Arthrodesis Technique (ACAT) provides many advantages, including minimal soft tissue disruption, ease of deformity correction, early rehabilitation, and a high rate of union. Ninety-one percent of the patients were satisfied, and 89% had a significant diminution of their pre-operative pain. Ankle arthroplasty, the only other option currently available, has shown disappointing results in the past, and newer designs have only seen short term follow-up.

Conclusion: The Anatomic Compression Arthrodesis Technique (ACAT) results in a low incidence of nonunion and a high level of patient satisfaction, is easily reproducible, and should be considered as the current treatment of choice for this difficult problem.