Mid- to Long-Term In Vivo Polyethylene Wear Rates in Salto Talaris Total Ankle Arthroplasty.

BACKGROUND

Polyethylene wear particles have been shown to be a contributing factor of osteolysis and aseptic loosening. To date, no clinical study has investigated the in vivo wear rates of Salto Talaris total ankle arthroplasty (TAA). Therefore, the purpose of our study was to evaluate mid- and long-term outcomes and in vivo wear rates in primary total ankle arthroplasty and their association with peri-implant osteolysis, complications, and implant survivorship.

METHODS

A retrospective review was performed to determine the mid- and long-term in vivo polyethylene wear rates in primary TAA. Patients with a minimum of 5-year clinical and radiographic data from a primary TAA with a fixed-bearing, semiconstrained, ultrahigh-molecular-weight polyethylene (UHMWPE) system were identified and included in this study. Polyethylene wear rates at final follow-up were analyzed using anteroposterior ankle radiographs and a validated computer-assisted Roman software. In addition, demographic data, peri-implant osteolysis, complications, reoperations, and revisions were recorded.

RESULTS

Fifty-four patients with a mean follow-up of 8.1 years (range, 5.2-13.0) were included in this study. The median polyethylene wear rate for the entire cohort was 0.06 mm/y (95% CI 0.04-0.08). Linear wear rate was found to have no true correlation relationship with patient age, BMI, or polyethylene size. More than half of patients (57%) demonstrated some radiographic signs of peri-implant osteolysis or cysts at final follow-up; however, comparative analysis investigating the relationship between wear rate and peri-implant osteolysis found no significant difference in wear rates for patients with tibial or talar osteolysis compared with those without (P = .451 and P = .434, respectively).

CONCLUSION

UHMWPE in this primary TAA demonstrated low in vivo wear rates. Rates of peri-implant osteolysis remain high with no clear association between wear rates and osteolysis.