Abstract
Optimal positioning of the acetabular component improves the long-term success of total hip arthroplasty by reducing the rate of adverse outcomes, such as component wear and dislocation. Mechanical guides designed to facilitate proper component orientation are inadequate, as they do not account for variations in patient position and pelvic motion during surgery. Pioneering image-guided surgical navigation systems were developed to provide surgeons with improved methods for intraoperatively measuring orientation and alignment. Although enhanced orientation has been reported with such systems, they require preoperative CT scans and are therefore limited by the need for preplanning, the necessity of matching CT data with the actual patient position, and the additional costs associated with CT. The recent development of CT-free navigational tools addresses these disadvantages and offers real-time surgical feedback regarding the actual position of the acetabular component and instruments relative to the pelvis. Proper training and enhanced identification of bony landmarks will improve upon the success of these systems.