Femoral Component Revision With Hydroxyapatite Coated Revision Stems

Abstract

Revision following major femoral component loosening can be difficult, both in terms of finding a means of stable fixation of the revision implant and in terms of finding viable bone stock. Adequate primary stability must be obtained, in order to allow the restoration of the badly damaged bone around the new implant, and to ensure the sound and lasting integration of the new device. This means that specially designed implants will be required so as to obtain the necessary primary stability and to find a solution to the individual patient's needs. Stability will be a function of the preoperative condition of the femur (granulomas, osteolysis, fractures, implant breakage) and of what happens at revision surgery (inadvertent perforation, fractures, cortical windows, Wagner osteotomy). Two Corail HA-coated implants are available. The KAR, a long-stem Corail specially designed for revisions, allows most cases of femoral loosening (Paproskyl Types 2A, 2B, and 3A) to be managed. Where there are major defects following loosening (Types 2C and 3B), or after transfemoral osteotomy, fixation will have to be sought in the diaphysis, and a modular screw-locked device such as the Reef will need to be used so as to obtain sufficiently distal fixation and to reconstruct the femur (figs 1 and 2).