Abstract
Aim
The purpose of this clinical series is to prospectively review the mid-term clinical and radiographic outcomes of the Scandinavian Total Ankle Replacement (STAR) performed at two academic Canadian University centres.
Methods
Between 1998 and 2005, 111 STAR were implanted into 98 patients at two Canadian centres. Prospective clinical and radiographic follow-up was performed. Validated and non-validated outcome questionnaires consisting of the AAOS foot and ankle questionnaire, AOFAS Hindfoot score, Foot Function Index (FFI), Ankle Osteoarthritis Scale (AOS) were completed. Sixty four patients were followed with these scores prospectively and 50 retrospectively. Both groups had prospective radiographic follow-up using measures described by Hintermann et al, and Wood et al.
Results
The average follow-up for both groups was 6.3 years (4.6-8.5 years). Of the 111 implanted STARs, 12 (11%) STARs had a metal component revision performed giving an overall survival of 89% (99) of the originally implanted metal components at the conclusion of the study. Thirty five patients (32%) had a re-operation performed during the follow-up period, 15 procedures (14%) were for replacement of fractured polyethylene liners. The sustained benefit across questionnaires from the STAR persisted to final follow up. Some evidence of osteolysis was present in 110/111 (99%) ankles at the final follow-up, more commonly around the talar component. No significant differences between the two centres in pre-operative or intra-operative data were identified.
Conclusion
The STAR, in the mid-term, shows acceptable survival and revision rates. There are, however, some concerning findings on radiographic follow-up. Further investigation and longer follow-up is required to substantiate these concerns.
