Abstract
Performing orthopaedic interventions with reduced trauma to soft tissue is considered a way to shorten recovery time and improve surgical outcome. Based on an analysis of causes of invasiveness in orthopaedic surgery, associated fields of development are described that aim at the reduction of invasiveness. The causes in question are the need to have visual contact to the performed surgical action, to guide surgical instruments into the situs, and to introduce devices such as screws, plates, or endoprostheses for implantation. This article focuses in particular on the use of navigation technology as a visualization aid to overcome the first cause of invasiveness. Two pay-offs of this approach are discussed which have so far prevented computer-assisted surgery systems from being used less invasively than conventional instruments. Referencing of the anatomy is required to track the spatial position and orientation of the operated bone. Registration establishes a systematic link between all objects involved. Alternatively, contact-less solutions have been proposed for both actions; however, up to now with only limited success. Current trends in robotically supported surgery seem to indicate that this technology may play a more important role in minimally invasive interventions in the future.