Stem damage during implantation of modular hip prostheses

Modular hip prostheses are commonly used today. Dedicated surgical auxiliary instrumentation is indispensable. A correct coupling between the prosthesis and the instrument is necessary to avoid damage. Based on a specific commercial design (AnCAFit, Wright Cremascoli Ortho, Toulon, France), the aim of this work was to assess if stem holders of modular prostheses can induce any stem damage, and if so, to identify the features that provide minimal damage. Two different stem holder connector designs were investigated. The surface of the stem cavity was inspected to identify the damage caused by the use of the two connectors after a simulated surgical handling. Both connectors induced some damage, with significantly more damage being caused by a supposedly improved design. Scars due to contact with the stem holder were observed on the stem cavity surface. This may be sufficient to trigger increased fretting damage during service life, causing the production of fretting debris.