The Hintegra Total Ankle Replacement: survivorship, failure modes and patient reported outcomes in 70 consecutive cases with a minimum 5 year follow up

L. Clifton, A. Kingman, P. Rushton, A. Murty, R. Kakwani, J. Coorsh, D. Townshend

Introduction: We report the functional outcome and survivorship of the Hintegra Total Ankle Replacement (TAR), in consecutive cases by multiple surgeons in a single UK institution. Between 2010-2014 the Hintegra TAR held 7.1% UK market share and surgeons should be aware of failure mechanisms.

Methods: We conducted a retrospective review of prospectively collected data for 70 consecutive Hintegra TAR cases in a single institution between 2010-2014. Data collected included patient demographics, complications, reoperations, patient reported outcome measures (PROMS: AOS, MOX-FQ, pain VAS) and patient satisfaction.

Results: The 70 patients (54 male/ 16 female) had an average age of 69 (range 48-84 years). Mean follow up was 76 months (range 60-104), 10 patients died during the follow up. Implant survivorship was 81.4% at most recent follow up. The commonest radiographic finding was periprosthetic cysts (n=28, 40%), size range (7-40mm), location of cysts: isolated talus (n=14), isolated tibia (n=6), mixed (n=8). 10 failed TARs were revised to Inbone TAR at a mean of 48 months (range 9-69). 3 Failed TARs were revised to arthrodesis (2 tibiotalar fusions, 1 hindfoot nail). 11 patients required reoperation with implant retention: 8 periprosthetic cyst debridement and grafting at a mean of 61 months (range 27-91), 1 lateral gutter debridement and 1 periprosthetic fracture ORIF. PROMS data was available for all patients. Overall patients showed marked improvement in functional outcome scores between pre-operative and final follow up questionnaires. Mean pre-op AOS: 62, MOX-FQ: 68 and pain VAS: 67.5 with mean final follow up scores of: AOS: 35, MOX-FQ: 36 and pain VAS: 30.

Conclusion: Our experience demonstrates improved PROMS following ankle arthroplasty for patients with a mean follow up of 6.4 years. Implant survivorship is similar to other TAR studies. We have identified a high incidence of periprosthetic cysts and would recommend ongoing surveillance of these patients.