Acetabular component positioning in minimally invasive total hip arthroplasty: comparison of conventional and image-free computer assisted assessment

摘要

Introduction: In performance of total hip arthroplasty, positioning of the acetabular cup is variable. Extremes of component malposition are associated with an increased risk of dislocation and loosening. In the case of metal on metal arthroplasty, such malposition can lead to acetabular loosening and high serum cobalt levels from edge impingement. Several reports have cited the accuracy with which implants can be placed using computer assisted robotic devices or surgical navigation. We proposed to study the reproducibility of acetabular component insertion into a cadaveric specimen in a simulated operating room environment utilizing a minimally invasive surgical approach. The surgical approach was the minimally invasive anterolateral approach which is made through an anterior interval preserving the gluteus medius muscle. We wanted to compare the surgeon's ability to assess acetabular component positioning after the use of conventional instrumentation and with the digital measurements following computer assisted placement using an optical image-free referencing system. The acetabular component position was then compared to measurements determined by utilizing a computed tomography protocol and coordinate measuring machine (CMM).