Long-term results of a vitamin E-blended polyethylene liner in total hip arthroplasty: a minimum ten year computer aided design based evaluation of wear and component positioning.

BACKGROUND

Aseptic loosening remains a leading cause of revision in total hip arthroplasty (THA), with polyethylene wear representing a key contributing factor. Vitamin E-blended highly cross-linked polyethylene (VEPE) has been introduced to improve oxidative stability and long-term wear performance; however, long-term clinical data remain limited.

METHODS

This retrospective study evaluates long-term polyethylene wear and component positioning in a cohort of patients who underwent primary THA using a vitamin E-blended polyethylene monoblock acetabular component (RM Pressfit vitamys®). Patients were followed for a minimum of ten years. Radiographic assessment was performed using a fully automated, observer-independent CAD-based software (RayMatch®), enabling measurement of cup inclination, anteversion, and polyethylene wear through 2D-3D registration of implant CAD models.

RESULTS

A total of 57 hips with complete radiographic follow-up were analyzed. Mean polyethylene wear rates were 26.9 µm/year at five years and 18.2 µm/year at ten years, remaining well below commonly reported thresholds associated with osteolysis. Cup inclination remained stable over time, whereas a gradual increase in measured anteversion was observed during follow-up.

CONCLUSION

At a minimum ten year follow-up, the investigated vitamin E-blended polyethylene monoblock cup demonstrated favorable long-term wear characteristics and stable component positioning. Further comparative studies are warranted to compare its long-term performance with other acetabular cup and liner designs.