Review of wear mechanisms in hip implants: Paper I – General

A review of wear mechanisms has been carried out in this paper for the hip prostheses. The primary causes of premature failure in hip prostheses are due to wearing of the implants. Multiple variables interact and increase the resultant wear rates. A summary of clinical in vivo and bulk material wear rate data from published literature has been presented for polyethylene-on-metal, metal-on-metal, and ceramic implants. This article addresses the engineering aspects concerning the advantages and disadvantages of each type of articulation. Wear mechanisms are discussed as a function of contact stresses, lubricants and clearance, surface hardness and roughness, type of articulation due to motion, number of cycles, solution particle count and distribution, oxidation of materials, and surface abrasions of both metal and polyethylene particulates. These issues are reviewed in this review.