Hip resurfacing is a technically demanding surgical procedure. Notching of the femoral neck and mal positioning of the femoral Implant are the most frequently seen complications in hip resurfacing. Navigation is expected to bring additional safety and precision to the surgical procedure. Goal of this pilot study is to check usability and reliability of a new application developed for an established navigation system for Orthopedics.

During a first developer release of the application 28 patients have been operated in 4 hospitals (Belgium, Canada, Germany and United Kingdom) from 2005-11-14 to 2005-12-22 with a Hip Resurfacing Implant (Durom®, Zimmer). The patient group consisted of 23 man and 5 women with an average age of 46 years (ranging from 29 to 66 years), mostly with primary cox arthrosis as indication. 7 surgeons have been navigating the femoral preparation with a therefore developed application on the Navitrack® system (ORTHOsoft Inc.). The protocol includes preoperative X-ray, intra-operative data and postoperative X-ray.

The mean Operation time (Incision to Closure) was 124 minutes (ranging from 88 to 150 minutes). In two cases navigation needed to be aborted due to mechanical failure of the instrumentation (K-wire jammed in guide) and surgery has been completed with the conventional instrumentation. The remaining cases have been completed without any Software or Hardware problems. The additional time required for navigation during those first cases has been approximately 10 minutes. In all cases the planned CCD angle was achieved within a range of +/− 5° without notching the femoral neck.

Navigation has the potential to improve precision in placement of the femoral component. The pilot study did prove the usability, safety and precision of the new Navitrack® CAS Durom Hip Resurfacing application. Combined with the already available cup navigation the system has an attractive potential to provide a tool helping the surgeon in achieving optimal outcome of a hip resurfacing.