Early outcomes of the TARIC mobile-bearing total ankle arthroplasty

The TARIC total ankle prosthesis is a low-profile, mobile-bearing implant. To date, no outcomes of this implant have been reported. This study evaluated the early clinical and radiological outcomes of this implant with a minimum follow-up of two years.

We retrospectively reviewed 85 consecutive cases (79 patients) of TARIC total ankle arthroplasty (TAA) performed by two surgeons between January 2021 and December 2022. The mean age of the cohort was 68.5 years (41 to 83), with a minimum follow-up of 24 months (mean 33.2 months (24 to 44)). The primary clinical outcome was the Ankle Osteoarthritis Scale score measured over the two-year follow-up. Radiological outcomes were assessed by measuring coronal plane alignment, identifying periprosthetic radiolucent lines or areas, and evaluating component subsidence or loosening. Postoperative complications and concomitant procedures at index surgery were also recorded.

All clinical outcome variables significantly improved, with three patients who underwent implant removal excluded from the analysis (p < 0.001). The mean tibiotalar and talar tilt angles improved to 4.9° (SD 2.8°) and 1.8° (SD 2.4°), respectively (p < 0.001). Radiolucent lines were most frequently observed at the bone-tibial component interface (38.8% (33/85)) and the fin of the tibial component (15.3% (13/85)). Periprosthetic radiolucent areas ≥ 5 mm were observed in 17 ankles (20.0%), and 16 ankles (16.5%) exhibited subsidence < 5 mm, which is relatively higher than previously reported rates in other implant systems. Three cases required implant removal, resulting in an implant survival rate of 96.5% at 24 months.

Early clinical outcomes and survivorship of TARIC TAA were comparable to previous reports on other total ankle systems. However, the relatively high rate of periprosthetic radiolucency and component subsidence warrants careful long-term monitoring.