Targeting Core Decompression and Cell Therapy Injection of Hip Osteonecrosis with Computer-Assisted Navigation.

Purpose: Surgical treatment of hip osteonecrosis with stem cell therapy is a new procedure in which cells are injected with a trocar under fluoroscopic guidance. Proper surgical technique to obtain appropriate placement of the trocar in the center of the osteonecrosis is sometimes difficult and can require additional radiation exposure until the surgeon is satisfied with the trocar position. This study describes an improvement of this procedure using computer-assisted navigation.

Methods: A prospective, randomized study was conducted on cadavers using surgical trainees with no experience and one expert surgeon in surgical core decompression. During a training session, 3 novice surgeons underwent a test by performing the surgical task (core decompression) on a cadaver hip using fluoroscopic guidance. These trainee surgeons then placed the Kirschner wire under computer-assisted navigation. Osteonecrosis was defined as a target volume situated on the superior and anterior part of the femoral head. Performance during the tests was evaluated by radiographic analysis of trocar placement and by the measurement of radiation exposure.

Results: During the cadaver session, computer-assisted navigation achieved a better match to the ideal position of the trocar, with better trocar placement in terms of the tip-to-subchondral distance and the ideal center position. Computer-assisted navigation was associated with fewer attempts to position the trocar, a shorter duration of fluoroscopy, and decreased radiation exposure compared to surgery performed under conventional fluoroscopy.

Conclusions: The findings suggest that computer-assisted navigation may be safely used to train surgical novices in core decompression. This technique avoids the use of both live patients and harmful radiation. For expert surgeons, computer-assisted navigation might improve precision with less radiation, which might be desirable in cell therapy.