Evaluation of fretting wear on the femoral stem surface

Fretting wear on polished femoral stems has been well documented in clinical reports, but in vitro simulation to replicate this wear has seldom been attempted and only limited success has been achieved. In the present study, fretting wear was successfully reproduced on the stem surface by incorporating initial stem implantation in a sawbone through bone cement and utilisation of saline solution to mimic in vivo conditions. The stem was examined through optical microscopy, optical interferometry and scanning electron microscopy. In addition, a technique was developed to identify fretting wear based on grey scale threshold, and a grid coordinate system was designed to relocate the position on the stem surface. This study gave scope for comparative investigation concerning the influence of femoral stem design, bone cement brand on generation of fretting wear.