Difference of Wear Damage of the Miller-Galante 1 and 2 Polyethylene Tibial Components

Won, Choong Hee; Park, Kyoung Jin

Abstract

PURPOSE: The purpose of this study was to examine the effects of change of polyethylene resin type and manufacturing method on the wear of polyethylene tibial component.
MATERIALS AND METHODS
Thirteen MG I and 10 MG II components were retrieved at revision surgery. Each polyethylene tibial component was graded for surface wear damage. Density profiles of the polyethylene were measured to examine the extent of oxidative degradation of the polyethylene.
RESULTS
The primary damage mode of the MG I retrievals was scratching and metallic debris, but the primary damage mode of the MG II was delamination (P<0.05). For the implants with implantation time of 5 years or more, the MG II polyethylene had a higher density value (0.959+/-0.002 g/cc, n=7) compared with the MG I (0.948+/-0.004 g/cc, n=11). Both delamination and polyethylene degradation increased with length of implantation time for the MG II components (P<0.01). Even after gamma sterilization, the directly molded 1900 MG I components experienced significantly less delamination and degradation than the machined GUR 415 MG II tibial components.
CONCLUSIONS
This study suggests that delamination of polyethylene tibial components is influenced by resin type and/or manufacturing method