Preoperative planning in pelvic and acetabular surgery: the value of advanced computerised planning modules.

An experimental computer program for virtual operation of fractured pelvis and acetabulum based on real data of the fracture is presented. The program consists of two closely integrated tools, the 3D viewing tools and the surgeon simulation tools. Using 3D viewing tools the virtual model of a fractured pelvis is built. This procedure is performed by computer engineers. Data from CT of a real injury in DICOM format are used. With segmentation process each fracture segment becomes a separate object and is assigned a different colour. The virtual object is then transferred to the personal computer of the surgeon. Bone fragments can be moved and rotated in all three planes and reduction is performed. After reduction, fixation can be undertaken. The appropriate ostheosynthetic material can be chosen. Contouring of the plate is performed automatically to the reduced pelvis. The screws can be inserted into the plate or across the fracture. The direction and length of the screws is controlled by turning the pelvis or by making bones more transparent. The modeling of the plate in all three axes can be recorded as the exact length of the screws. There is also a simulation tool for intraoperative C-arm imaging in all directions. All the steps of the procedure are recorded and printed out. Postoperative matching of real operation and virtual procedure is also possible. We operated on 10 cases using virtual preoperative planning and found it very useful. The international study is still in progress. One case is presented demonstrating all the possibilities of the virtual planning and surgery. The presented computer program is an easily usable application which brings significant value and new opportunities in clinical practice (preoperative planning), teaching and research.