Five-year comparative study of highly cross-linked (crossfire) and traditional polyethylene.

The purpose of this study was to compare the linear penetration rates of a highly cross-linked ultra-high-molecular-weight polyethylene to traditional polyethylene. Twenty-seven highly cross-linked components were matched to 27 traditional polyethylene components with respect to age, sex, body mass index, and activity level. Each group was followed up for a mean of approximately 6 years. Linear penetration was measured using Martell's computerized technique (J Bone Joint Surg Am 1997;79:1635). The mean total penetration was 0.283 mm (SD, 0.253) for the highly cross-linked group. The mean total penetration for the traditional polyethylene was 0.696 mm (SD, 0.402). This difference was highly significant (P < or = .001). Our experience demonstrates a 59% reduction in total penetration of highly cross-linked polyethylene when compared with traditional polyethylene at a minimum of 5 years.