Watson Extraction System for Femoral Stem Extraction

A revision total hip replacement surgery requires the surgeon to remove, or extract, the femoral stem (the rod that was placed into the thigh bone during your first hip replacement). A variety of tools and techniques can be used to do this. At The Ottawa Hospital (TOH) surgeons attempt to remove the stem using less invasive measures, such as osteotomes, a tool that separates the stem from the bone, but if it doesn't work, they may need to perform an extended trochanteric osteotomy (ETO). An ETO is more invasive and increases the risk of complications. The Watson Extraction System (WES) is another Health Canada approved tool that goes around the stem to help remove the femoral stem from the thigh bone. Research shows that the WES has been studied in case series of a few people, and the results seem promising, reducing the time of extraction and need for ETO. However, it is not clear if it offers better results than what is currently done at TOH. The purpose of this study is to compare the WES to the current/usual care care at TOH to determine whether the WES can remove the femoral stem more efficiently (in less time and at a lower hospital cost) and effectively, while improving patient safety.

Inclusion Criteria: * Over 18 years of age * Undergoing revision Total Hip Arthroplasty for septic or aseptic indications * Have well-fixed femoral components, of blade-stem design (collared and collarless) Exclusion Criteria: * Tapered stem in situ less than 4 months * Cemented Stems * Femoral Stems with Trunnions \> 14mm * Femoral Stems of alternative design not compatible for use with the WES