Gauging clinical practice: Surgical navigation for total hip replacement

Abstract

HipNav is a hip implant navigation and guidance system which helps surgeons plan acetabular implant orientation preoperatively, and guides them intraoperatively to achieve this intended plan. Through this process, these technologies are used to measure, gauge, and quantify current clinical practice. With HipNav, surgeons plan and execute the procedure in the 3-D realm with accurate patient models, taking advantage of anatomic information normally lost through traditional planning methods. During surgery HipNav tracks the alignment tool with respect to the pelvis, compensating for any pelvic motion, thereby ensuring an accurate measurement of alignment and placement according to the plan. This past year has seen the system move out of the developmental laboratory setting and into the operating room environment. In addition to its primary clinical function as a surgical assist device, through its measurement and tracking capabilities HipNav has likewise emerged as a powerful research tool. With HipNav we are now able to measure, for example, how the pelvis moves during surgery, how cup placement shifts during the press fit process, and how well traditional implant guides and strategies compare with new strategies based on more complete patient-specific models. HipNav is still an emerging technology and a continually evolving system. However, data collected to date through the HipNav project have provided new insight into aspects of the total hip replacement process, challenging commonly held assumptions concerning acetabular alignment. Most importantly, HipNav has indications for some areas of established practice that may benefit from reexamination.