This Small Business Innovation Research Phase II project is intended to support the further development and clinical testing of an image guided surgical system that will assist the surgeon in performing procedures that involve the insertion of a screw, guide pin, drill bit, or other linear object into bone. These surgeries are currently performed with the assistance of a mobile fluoroscopic x-ray imager (C-arm). Disadvantages associated with C-arms include image distortion, radiation exposure, and time consuming reconfiguration of the C-arm (between A/P and lateral views) during the insertion process. The proposed system would address these shortcomings with a computer-based system that augments the existing C-arm system. An optical localizer (an stereo camera device that tracks light emitting diodes) is used to monitor the location and orientation of a drill guide in the surgical field. The drill guide trajectory is then graphically superimposed on the x-ray images. This provides real-time, on-screen positional feedback to the surgeon to improve the accuracy and speed with which certain procedures involving insertion of drill bits or guide pins can be performed. The research effort will focus on the development of a clinical prototype and its evaluation by several quantitative and qualitative methods. The commercial success of such a system depends on its acceptance by surgeons, which in turn depends on the extent to which it is a tool that provides better information to the surgeons without intruding on a procedure in which they are already highly skilled. Commercial success also depends on the ability of the system to reliably provide time savings in the operating room. These issues will be addressed by cadaveric studies and subsequent clinical trials. PROPOSED COMMERCIAL APPLICATIONS: The initial commercial application of this system is the insertion of dynamic compression hip screws in cases of hip fracture. Because this is a common fracture, any reduction in surgical time has great potential for cost savings. Other advantages including decrease in radiation exposure and the potential reduction of serious complications. Minor modifications that allow the system to assist with numerous other orthopaedic trauma procedures are already planned.