An attempt to use Computer Assisted Orthopedic Surgery in the diagnosis and treatment of hip deformations.

Background. Computer Assisted Orthopaedic Surgery (CAOS) enables complex 3D planning of surgery and the precise navigation of surgical instruments or implants during the operation. This procedure may also be helpful in preparing pelvic osteotomies, by enabling a pre-operative, virtual assessment of the results of the surgery. The purpose of this paper is to present the possibilities of our "Super Pelvis" software in assisting the diagnostics and treatment of diseases of the hip. Material and methods. We have developed a soft-ware program called "Super Pelvis," which enables 3D reconstruction of any part of the skeleton based on CT scans. It also enables 3D qualitative assessment of the whole pelvis by rotation and magnification. The material consisted of 30 dry, healthy adult skeletons gained from a medieval cemetery. In every pelvis both acetabuli were examined three times to measure the modified center-edge angles (CEA) and the anterior and posterior sector angles. The first step was a morphologic examination based on two photographs taken in frontal and transverse view. X-rays were also taken in the same views as the photographs to assess the same parameters. Then these same parameters were measured using "Super Pelvis." Results and Conclusions. All three methods of measurement have high reproducibility and there is statistically significant correlation between them. The "Super Pelvis" soft-ware seems to be useful in the precise measurement of parameters describing the acetabulum. This is the first step in creating a software package for intra-operative navigation in pelvic surgery.