Mobile bearing ankle prosthesis in the longer term

The use of total ankle arthroplasty is becoming more acceptable, with patients and clinicians alike now expecting reasonable ten-year survivals and functional outcomes. There are very different designs of ankle replacement, varying in major as well as minor design features. The Scandinavian Total Ankle Replacement (STAR) is a widely accepted implant, with proponents arguing that the mobile-bearing design with a mature surgical technique should yield excellent results. Surgeons in Nijmegen (The Netherlands)⁷ have shared their experience of the STAR at an average of ten years’ (minimum of 7.5 years) follow-up. In line with many other series, the survival was around 80% at ten years, with the majority of failures undergoing explantation and fusion. There was a high reported rate of complications with fractured polyethylene inserts (10.4%), other complications (22%), and 16% of patients required further surgery for these complications. Heterotopic ossification was seen in around 70% of patients and 60% had visible expanding osteolytic lesions. This report represents a ten-year experience in a reasonably sized centre, and is in line with the survivals seen in other longitudinal series. The authors of this series report honestly their own experience and it highlights the vast number of patients experiencing complications following total ankle replacement, both those who require revision surgery, and those who are likely to do so in the future. It is very welcome that many of the large joint registries are now including data surrounding ankle and elbow arthroplasties which are historically less commonly performed, and currently the only data to support their use almost pose as many questions as they answer. We look forward to reports from these registries when there is enough follow-up to allow for accurate estimation of longer-term survival.