Computer-Assisted Orthopedic Surgery (CAOS): Pros and Cons

Abstract

Computer-assisted orthopedic surgery (CAOS) has recently evolved as an important technical application that has offered substantial improvements over conventional instrumented methods. The possibility of using computers in total joint replacement surgery is not a recent discovery, as Bargar and Paul introduced the first successful robotic application for total hips in 1987.¹ Their system was a development effort with IBM, which had identified a considerable research program to apply robotics to medicine. Perhaps the most significant discovery at the time was to refine digital software algorithms to the level of “pixel accuracy” (20–30 μm). This was required for the machining of custom total hip femoral implants that were implanted at that time. The next years of evolution occurred in Europe, where computer algorithms were advanced to allow intraoperative registration, removing the need for preoperative fiducial placement. DiGioia and Jaramaz developed the first computed tomography (CT) system that could be applied for navigation of the acetabular component.² Actually, this approach was a step backward because the complex robot was not needed. Imageless total knee applications were an even simpler method because preoperative images were no longer needed.

From a purely scientific point of view, the proof of these systems for increasing surgical precision and presumed benefit has been straightforward. The literature that I will outline clearly indicates the benefit of computer-assisted techniques over conventional instrumentation. Even in imageless total hip applications with lesser accuracy, computer-assisted surgery (CAS) provides a statistical improvement over conventional techniques from most studies. In this chapter, I offer a broad overview of the current state of the art. As with minimally invasive surgery (MIS), there are a group of early advocates who may offer a more enthusiastic viewpoint. As demonstrated, I will describe my current experience and research, which would question some of the claims regarding electromagnetic applications and imageless total hip applications, for example. However, this technology is a moving target, and improvements are being developed as we speak.