Analysis of retrieved hemiresurfacing implant.

The aim of this study was to examine the bony interface underlying a femoral hemiresurfacing implant. The specimen was subjected to radiographic and histologic analyses. The presence of a cement mantle was not uniform throughout the interface. When cement was evident, trabecular bone was found interdigitated within the mantle. When cement was not present, a fibrous tissue membrane was detected between the metal surface of the implant and the host bone. Disruption of the bone stock surrounding the stem was observed. While the reason for the revision was for relief of severe pain for acetabular chondrolysis, bony support of the implant may have been compromised.