OBJECTIVETo provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique.

METHODSPelvis image data were obtained from three-dimensional CT scan in patients with sacral fracture. The data were transferred into a computer workstation. The three-dimensional models of pelvis were reconstructed using Amira 3.1 software and saved in STL format. Then the three-dimensional fracture models were imported into Imageware 9.0 software. Different situations of reduction (total reduction, half reduction and non-reduction) were simulated using Imageware 9.0 software. The best direction and location of extract iliosacral lag screws were defined using reverse engineering according to these three situations and navigation templates were designed according to the anatomic features of the postero-iliac part and the channel. The exact navigational template was made by rapid prototyping. Drill guides were sterilized and used intraoperatively to assist in surgical navigation and the placement of iliosacral lag screws.

RESULTSAccurate screw placement was confirmed with postoperative X-ray and CT scanning. The navigation template was found to be highly accurate.

CONCLUSIONThe navigation template may be a useful method in minimal-invasive fixation of sacroiliac joint fracture.