Evaluating Failure Mechanisms for Total Talus Replacement: A Case Series

Abstract

Category: Ankle Arthritis Introduction/Purpose: Talar collapse can occur from a variety of etiologies and may pose a unique challenge to the foot and ankle surgeon due to the complexity of the deformity and associated adjacent joint degenerative change. Total talus replacement (TTR) has emerged as an attractive option to help patients return to activities sooner than with arthrodesis and improve pain and joint mechanics postoperatively. However, there is limited long-term data on the most recent generation of implants. In this multi- institution case series, we present the severe complications that can occur after TTR, including instability, infection, and adjacent joint osteoarthritis. Methods: We present three cases from Duke University Hospital in Durham, North Carolina, and the Hospital for Special Surgery In New York City, New York. All three patients were treated with a total talus replacement (TTR) during their clinical course and experienced subsequent complications. Clinical data and radiographs were collected from chart review under an IRB-exempt protocol. Results: Case 1 demonstrates the risk of ligamentous insufficiency leading to dislocation following placement of a TTR. This case highlights the posterior instability due to soft tissue mobilization and division. Case 2 highlights the risk for adjacent joint degeneration with TTR. Case 3 presents an instance of non-union following a total ankle and total talus replacement (TATTR) with subtalar arthrodesis. To our knowledge, this represents the first case of nonunion following TTR in the literature. Finally, we discuss our institution’s experience with infection following TTR and possible contributing factors to this specific procedural risk. Conclusion: TTR shows promise in the properly selected patient with end-stage talar collapse. However, heterogeneous surgical techniques, implant composition, indications, and patient demographic variables complicate the interpretation of the literature. Moreover, few studies report mid-to long-term outcomes after this procedure and the occurrence of adjacent joint OA is likely underreported in the literature. Thus, until further, high-quality studies with long-term follow-up validate the positive early outcomes of TTR, we urge extreme caution in patient selection, choice of implants, and surgical techniques.