Percutaneous computer assisted iliosacral screwing: Clinical validation

Abstract

This paper describes the clinical validation of an image-guided system for the percutaneous placement of iliosacral screws. The goals of the approach are to decrease surgical complications, with a percutaneous technique, and to increase the accuracy and security of screw positioning thanks to a computer assisted system. Pre-operative planning is performed on CT-scan images and a 3D model is built. During surgery, tools are tracked with an optical localizer. An ultrasound acquisition is performed and images are segmented to obtain 3D intra-operative data that are registered with the CT-scan 3D model. The surgeon is assisted during drilling and screwing processes with re-sliced CT-scan images displayed on the computer screen and comparison between pre-operative planning and tools position. The system was validated in a cadaver study [1l The clinical validation has then started and four patients have been successfully instrumented.