Surface finish mechanics explain different clinical survivorship of cemented femoral stems for total hip arthroplasty.

Overview

The ability of bone cement to adhere to the implant surface is dependent on the surface finish. Stems with a rough surface finish require greater force to disrupt their interface with the cement than do stems with a smooth or polished surface. However, if micromotion occurs at the cement-metal interface, the fretting of a smoother surface implant results in less cement and metallic abrasion than an implant with a rough surface finish. Today, surgeons implant femoral stems with a wide variety of surface finish and textures that are supported by the previously mentioned contrasting philosophy of fixation. This article presents the micro and macro surface finish mechanics, history, and rationale for changes in surface finish, the clinical and operative implications of changes in surface finish, the retrieval analysis, and the clinical evidence that examine the consequences of changes in surface finish in the outcome of cemented femoral stems for total hip arthroplasty. Current data and our own experience support the use of cemented femoral stems with a smooth or polished surface finish.