[Limits of CT-based computer navigation in spinal surgery].

Computer-assisted and navigation-based therapeutic tools have found their first application in the field of spinal surgery. Meanwhile, the basic principles have been extended to other procedures, such as screw osteosynthesis of the pelvis and navigation of long bones. Commonly, all procedures except C-arm navigation are based on three-dimensional data sets. Data acquisition and processing as well as planning require specific steps, which should guarantee adequate accuracy and successful navigation. All steps up to intraoperative navigation and potential pitfalls in every part of the interaction are demonstrated, with reasons of undesired results presented.