SLR - April 2019 - Anusha Iyer

Survivorship and Long-Term Outcome of a Consecutive Series of 200 Scandinavian Total Ankle Replacement (STAR) Implants

Reference: Clough, T., Bodo, K., Majeed, H., Davenport, J., Karski, M. Survivorship and long-term outcome of a consecutive series of 200 Scandinavian Total Ankle Replacement (STAR) implants. Bone Joint J. 2019 Jan;101-B(1).

Scientific Literature Review

Reviewed by: Anusha Iyer, DPM
Residency Program: Montefiore Medical Center, Bronx, NY

Podiatric Relevance: Ankle arthritis is a common ailment presenting to the podiatric practice. While posttraumatic arthritis is the leading etiology, many are affected by other causes. While there is a plethora of conservative therapy, there are two main surgical treatment options: arthroplasty or arthrodesis of the ankle joint. Due to the debilitating nature of the ailment, patients will often pursue surgical treatments despite their great risks. This study offers a standard to compare all other future implants by analyzing the long-term functions and implications of the Scandinavian Total Ankle Replacement (STAR) implants on 184 patients.

Methods: This is a prospective study evaluating the long-term outcomes of 200 STAR implants (184 patients) between November 1993 and February 2000 conducted by one surgeon in Wrightington Hospital, Wigan, UK. Indications for TAA were inflammatory joint disease, osteoarthritis and posttraumatic osteoarthritis. Tourniquet was used in all surgeries with three doses of prophylactic antibiotics. Approach to all surgeries was via the anterior ankle. American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scoring system was used to evaluate pain and function of all surviving patients. The primary outcome was failure of the implant, defined as need for revision surgery. The rate of failure of the implant was calculated using the Kaplan-Meier survival curves.

Results: The mean follow-up was 15.8 years. Of the 200 STAR implants, 32 failed requiring either an ankle fusion, tibiotalocalcaneal fusion or exchange of polyethylene insert. On average, time to revision was discovered to be 80 months. Eighteen of 32 implants failed due to aseptic loosening of the implant, contributing to the major reason for implant failure. The second major reason was edge-loading of the implants, which caused polyethylene component of the implant to break down faster. Delayed wound healing affected five ankles in this cohort. One hundred out of the 184 patients died during this study.  

Conclusions: The authors of this study concluded that the STAR implant provides a durable alternative to the historical ankle arthrodesis. This study concluded that there is a higher rate of revisional surgeries during the early postoperative years. The study found long-term survival rates at five years (90.41 percent), 10 years (82.76 percent) and 15.8 years (76.16 percent). The authors conclude that this study can be used as an appropriate benchmark for comparative analysis of newer implants.

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