Vitamin E-stabilized polyethylene shows similar survival rates at minimum 7-year follow-up compared to conventional polyethylene in primary total knee arthroplasty.

ABSTRACT

Purpose: The aim of this cross-sectional study was to compare survival, clinical and radiographic results of total knee arthroplasty (TKA) with vitamin E-stabilized polyethylene (VEPE) or conventional polyethylene (CPE) at a minimum of 7-year follow-up. Methods: Patients who underwent primary TKA between 2011 and 2015, receiving the same cemented rotating platform knee design with VEPE or CPE tibial inserts, were identified. Patients were contacted for clinical and radiographic follow-up. American Knee Society Score (KSS), Forgotten Joint Score (FJS-12), presence of periprosthetic radiolucent lines (RLLs) and osteolysis were evaluated at the last follow-up. Any revision, reintervention or other complications were recorded. Results: Among 350 TKAs initially identified, 102 VEPE and 97 CPE knees were included for analysis with mean follow-up of 8.5 and 8.3 years, respectively. No significant difference was found in survival rates at 10-year follow-up with revision due to aseptic loosening (95.0% vs. 97.8%, p = 0.29) or due to any reason (87.6% vs. 89.6%, p = 0.78) between VEPE and CPE TKA. KSS function score resulted significantly higher in the VEPE group over CPE (77 vs. 63, p = 0.01). RLLs were more frequent in VEPE than CPE (54% vs. 32%, p = 0.05), mainly noticed medially and posteriorly beneath the tibial plate, adjacent to the trochlear shield and the posterior condyles. Osteolysis was observed in one knee per group, but patients were asymptomatic with stable implants. Conclusion: TKA with VEPE and CPE tibial inserts showed comparable survival rates, complications and clinical and radiographic results up to 10-year follow-up. Level of Evidence Level III.