6 Computer-assisted Minimally Invasive Spine Surgery State of the Art 6.2 Computer-assisted Orthopaedic Surgery

With the advent of precise preand intraoperative imaging means, the development of sophisticated image data visualization, and the accessibility of submillimetric, real-time tracking of objects in space, surgical navigation systems have been created that aim at enhanced surgical accuracy and ultimately improved clinical outcome [3, 6, 9, 13, 17, 20]. Numerous studies have shown the superiority of computer-assisted versus conventional instrumentation at different levels of the spine regarding accuracy and thus potential safety [4, 14, 24, 25]. However, this technique has been less successful in contributing to the reduction of intraoperative invasiveness, although this aim has been anticipated by most of the pioneering authors [13, 17, 20]. It is the aim of this article to outline the basic principles of computer assistance for spine surgery, whichwill help the reader to understand why navigated interventions must be invasive in the first place. In addition, efforts towards less and minimally invasive procedures of the past and current research will be presented and discussed.