Computer-assisted orthopedic surgery

Abstract

Computer-assisted surgery (CAS) utilizing roboticor image-guided technologies has been introduced intovarious orthopedic fields. Navigation and robotic systems arethe most advanced parts of CAS, and their range of functionsand applications is increasing. Surgical navigation is avisualization system that gives positional information aboutsurgical tools or implants relative to a target organ (bone) ona computer display. There are three types of surgical planningthat involve navigation systems. One makes use of volumetricimages, such as computed tomography, magnetic resonanceimaging, or ultrasound echograms. Another makes use ofintraoperative fluoroscopic images. The last type makes use ofkinetic information about joints or morphometric informationabout the target bones obtained intraoperatively. Systemsthat involve these planning methods are called volumetricimage-based navigation, fluoroscopic navigation, andimageless navigation, respectively. To overcome theinaccuracy of hand-controlled positioning of surgical tools,three robotic systems have been developed. One type directsa cutting guide block or a drilling guide sleeve, with surgeonssliding a bone saw or a drill bit through the guide instrumentto execute a surgical action. Another type constrains the rangeof movement of a surgical tool held by a robot arm such asACROBOT. The last type is an active system, such asROBODOC or CASPAR, which directs a milling deviceautomatically according to preoperative planning. These CASsystems, their potential, and their limitations are reviewedhere. Future technologies and future directions of CAS thatwill help provide improved patient outcomes in a costeffectivemanner are also discussed.