Trends in Total Ankle Arthroplasty in Scotland

Introduction Total ankle replacement (TAR) is performed for post-traumatic arthritis, inflammatory arthropathy, osteoarthritis and other indications. The Scottish Arthroplasty Project (SAP) began collection of data on TAR in 1997. In this study, using data from the SAP, we look at trends in the use and outcomes of TAR in Scotland. Methods We identified 499 patients from the SAP who underwent TAR between 1997 and 2015 with imaging available on the National Picture Archiving and Communication System (PACS). We identified, and looked at trends in, implant type over the following time periods: 1998–2005; 2006–2010 and 2011–2015. Age, gender, indication and outcomes for each time period were examined and also trends with implant type over time. Results There were 499 primary TAR procedures with an overall incidence of 0.5/10 5 population per year. Eight different implants were identified with significant changes in the numbers of each type used over time. The peak incidence of TAR was in the 6th decade. The mean age of patients undergoing TAR from 59 years in 1997–2005, to 65 years in 2011–15 (p< 0.0001). The percentage of patients with inflammatory arthropathy was 52% in 1997–2005, compared with 10% in 2011–2015. Subsequent arthrodesis and infection rates appeared to be higher during the first time period. The female to male ratio also changed over time. The incidence of TAR increased overall during the study period (r= 0.9, p=< 0.0001). This may be due to a broadening range of indications and patient selection criteria, in turn due to increased surgeon experience and the evolution of implant design. Conclusion This study examines a large number of TARs from an established arthroplasty registry. The rate of TAR has increased significantly in Scotland from 1997 to 2015. Indication and patient age has changed over time and this could potentially impact outcomes after ankle replacement.