Aims. Despite the increasing numbers of ankle arthroplasties, there are limited studies on their survival and comparisons between different implants. The primary aim of this study was to determine the failure rates of primary ankle arthroplasties commonly used in the UK. Methods. A data linkage study combined National Joint Registry (NJR) data and NHS Digital data. The primary outcome of failure was defined as the removal or exchange of any components of the implanted device. Life tables and Kaplan-Meier survival charts were used to illustrate survivorship. Cox proportional hazards regression models were fitted to compare failure rates between 1 April 2010 and 31 December 2018. Results. Overall, 5,562 primary ankle arthroplasties were recorded in the NJR. Linked data show a one-year survivorship of 98.8% (95% confidence interval (CI) 98.4% to 99.0%), five-year survival in 2,725 patients of 90.2% (95% CI 89.2% to 91.1%), and ten-year survival in 199 patients of 86.2% (95% CI 84.6% to 87.6%). The five-year survival for fixed-bearing implants was 94.3% (95% CI 91.3% to 96.3%) compared to 89.4% (95% CI 88.3% to 90.4%) for mobile-bearing implants. A Cox regression model for all implants with over 100 implantations using the implant with the best survivorship (Infinity) as the reference, only the STAR (hazard ratio (HR) 1.60 (95% CI 0.87 to 2.96)) and INBONE (HR 0.38 (95% CI 0.05 to 2.84)) did not demonstrate worse survival at three and five years. Conclusion. Ankle arthroplasties in the UK have a five-year survival rate of 90.2%, which is lower than recorded on the NJR, because we have shown that approximately one-third of ankle arthroplasty failures are not reported to the NJR. There are statistically significant differences in survival between different implants. Fixed-bearing implants appear to demonstrate higher survivorship than mobile-bearing implants. Cite this article: Bone Joint J 2023;105-B(3):301–306

Aims

We report the long-term clinical and radiological outcomes of a consecutive series of 200 total ankle arthroplasties (TAAs, 184 patients) at a single centre using the Scandinavian Total Ankle Replacement (STAR) implants.

We performed a systematic review and meta-analysis of modern total ankle replacements (TARs) to determine the survivorship, outcome, complications, radiological findings and range of movement, in patients with end-stage osteoarthritis (OA) of the ankle who undergo this procedure. We used the methodology of the Cochrane Collaboration, which uses risk of bias profiling to assess the quality of papers in favour of a domain-based approach. Continuous outcome scores were pooled across studies using the generic inverse variance method and the random-effects model was used to incorporate clinical and methodological heterogeneity. We included 58 papers (7942 TARs) with an interobserver reliability (Kappa) for selection, performance, attrition, detection and reporting bias of between 0.83 and 0.98. The overall survivorship was 89% at ten years with an annual failure rate of 1.2% (95% confidence interval (CI) 0.7 to 1.6). The mean American Orthopaedic Foot and Ankle Society score changed from 40 (95% CI 36 to 43) pre-operatively to 80 (95% CI 76 to 84) at a mean follow-up of 8.2 years (7 to 10) (p < 0.01). Radiolucencies were identified in up to 23% of TARs after a mean of 4.4 years (2.3 to 9.6). The mean total range of movement improved from 23° (95% CI 19 to 26) to 34° (95% CI 26 to 41) (p = 0.01).

Our study demonstrates that TAR has a positive impact on patients’ lives, with benefits lasting ten years, as judged by improvement in pain and function, as well as improved gait and increased range of movement. However, the quality of evidence is weak and fraught with biases and high quality randomised controlled trials are required to compare TAR with other forms of treatment such as fusion.

Cite this article: Bone Joint J 2013;95-B:1500–7.