STAR™ Ankle: Long-Term Results

Abstract

Background: There has been a resurgence of interest in total ankle replacement (TAR) due to improved results with newer prostheses. However, long-term survivorship data has been limited. The STAR™ Ankle prosthesis is the first three-part prosthesis approved for use in the United States. Materials and Methods: Eighty-four total ankle replacements were performed in 80 patients using the STAR™ Ankle prosthesis and followed prospectively. Postoperatively, patients were evaluated with the AOFAS score for pain and function, and serial radiographs were evaluated for stability and alignment of the prosthesis. Implant failure, secondary procedures, and complications were recorded. Results: Ninety-one percent of prostheses remain implanted at an average followup of 9.1 years. The probability of implant survival was 96% at 5 years and 90% at 10 years. An average 39-point improvement in the AOFAS ankle-hindfoot score was noted, from a mean of 43 to a mean of 82 points. We noted a statistically significant increase in both average pain and function sub-scores. Postoperative range of motion averaged 4.5 degrees of dorsiflexion and 35 degrees of plantarflexion. Ninety-two percent of the patients were satisfied with their outcome. Ten patients (13%) developed concerning osteolytic lesions. Change in prosthetic alignment and adjacent joint arthritis were similar to previous reports. We report 21 complications, which included 14 additional surgical procedures. Conclusion: The first U.S. prospective long-term survivorship data with the STAR™ Ankle prosthesis found it to be an excellent long-term option for the treatment of ankle arthritis. Level of Evidence: IV, Case Series