The Infinity Total Ankle System: Early Clinical Results With 2- to 4-Year Follow-up

Aims. This study presents the first report of clinical and radiographic outcomes of the Infinity Total Ankle System (Wright Medical, Memphis, TN) with minimum 2-year follow-up. Patients and Methods. The first 67 consecutive patients who underwent primary total ankle arthroplasty (TAA) with the Infinity system at 2 North American sites between August 2013 and May 2015 were reviewed in a prospective, observational study. Demographic, radiographic, and functional outcome data were collected preoperatively, at 6 to 12 months postoperatively, and annually thereafter. Results. The overall implant survival rate was 97% (65 of 67 implants) at a mean follow-up of 35.4 months (27 to 47 months). Two cases underwent talar component revision for aseptic loosening. Six of the 67 cases (9%) required a nonrevision reoperation. Mean Foot Function Index and Ankle Osteoarthritis Scale scores at latest follow-up improved from preoperative by 21.6 (P < .0001) and 34.0 (P < .0001), respectively. No radiographic loosening of any talar or tibial components was identified in the 65 nonrevised cases. Conclusion. Early clinical and radiographic outcomes with the Infinity TAA are promising and compare favorably to those reported for both fixed- and mobile-bearing third-generation TAA designs, even when used in cases with deformity and increased case complexity. Levels of Evidence: Level IV