7 to 9 year survivorship of 106 fixed bearing total ankle replacements

M. Dahill, M. Kostusiak, M. Dean, A. Hughes, R Kakwani, A Murty, D. Townshend, I. Sharpe

We report the mid-term outcomes of a prospective series of fixed bearing total ankle replacements (TAR), from two non-designer centres. The primary aims were to assess survivorship and adverse events, including complications and re-operations. The secondary aims were to assess functional and radiological outcomes.

Data was collected prior to surgery and at annual follow up appointments, for patients operated on between March 2014 and December 2016. Implant survivorship, complications, reoperations and patient reported outcome scores (PROMS) were collected. Radiological data was also collected.

102 patients, comprising 106 TAR, were included in the study. Mean age at implantation was 68 years (range 42 to 89). Mean follow up time was 98 months (range 83 to 113). 4 patients were lost to follow up and 12 patients died. Mean age at the time of surgery for the 12 deceased patients was 84 years and the mean follow up time was 59 months.

12 patients received further surgeries; 8 revision TAR, 3 biopsy and grafting of talar cysts, and 1 capsular release. The reasons for revision surgery were unexplained pain (5 patients), proven deep infection (1 patient), tibial subsidence (1 patient) and instability (1 patient). Mean time to revision surgery was 43 months (range 15 to 82). Current survivorship of the cohort is 91% (82 of 90 TAR).

15 patients suffered complications of surgery. 7 patients exhibited delayed wound healing without deep infection, 6 patients sustained intra-operative medial malleolar fractures and 2 patients were diagnosed with chronic regional pain syndrome.

Radiolucencies were seen in 35% of patients. MOXFQ and EQ5D-5L PROMS showed significant post-operative improvements (p < 0.01).

6 to 9 years represents the longest follow up of this fixed bearing TAR to date. Survivorship is high and significant improvements in disease specific, and general health, PROMS were observed.