Grafted Vitamin-E UHMWPE may increase the durability of posterior stabilized and constrained condylar total knee replacements.

The suitability of grafted vitamin-E highly crosslinked polyethylene (VE-HXPE) for use in posterior stabilized (PS) and constrained condylar knee (CCK) applications has not been explored. We hypothesized that VE-HXPE performs better than conventional and crosslinked polyethylene under clinically relevant conditions. PS tibial post fracture resistance under adverse shear loading conditions, CCK tibial post resistance to torsional fatigue, delamination resistance under high stress, and wear resistance were evaluated.

The effect of entrapped bone particles on the surface morphology and wear of polyethylene.

Clinically retrieved highly cross-linked ultrahigh molecular weight polyethylene (HXPE) acetabular liners have demonstrated scratching, whereas conventional ultrahigh-molecular-weight polyethylene (UHMWPE) implants show a smoother surface early after implantation. In the present study, the potential of bone particles and soft tissues, rather than cement, to scratch the articular surface of HXPE and UHMWPE (gamma radiated) acetabular components was evaluated; multiple bone particles located at the articular surface for 3600 simulated walking cycles replicated the scratches observed on retrieved implants. By remelting, these scratches were confirmed to be due to plastic deformation of the polyethylene, not wear.