title: Head replacement, head rotation, and surface damage effects on metal-on-metal total hip replacements: a hip simulator study.
abstract: The possibility of replacing the femoral head alone, in either solid or articular surface replacement form, during revision operations on metal-on-metal total hip replacements remains an attractive feature of such implants. In the present investigation, laboratory simulator studies of the influence upon volumetric wear of inserting a new femoral head, of introducing some head rotation, and of damaging the femoral head by scratches have all been explored. New and rotated heads both involve an additional running-in period, but the experimental studies show that the volumetric wear associated with this process is less than the initial running-in wear. The beneficial effects upon volumetric wear of small clearances have been confirmed, while the processing of high-carbon Co-Cr-Mo materials appears to be much less influential. Scratches did not affect wear as much as head replacement or head rotation, but the ongoing wear rates were somewhat higher.
authors: DePuy International Limited, Leeds, UK.
authors: C
authors: C
authors: Hardaker
authors: D
authors: D
authors: Dowson
authors: G H
authors: GH
authors: Isaac