A study of the wear of explanted metal-on-metal resurfacing hip prostheses

Due to their recent introduction there are few studies of retrieved resurfacing hip prostheses. Nine such components associated with groin pain in patients, and five associated with early fracture of the femur, were obtained and analysed using a roundness measuring machine. While the ‘fracture’ components showed no more than 3 μm out of roundness, components associated with groin pain showed between 15 and 92 μm out of roundness values. These latter results indicate wear and correlated with high metal ion levels in these patients, therefore the groin pain was likely associated with an adverse reaction to excessive metal wear debris.