Application of navigation template to fixation of sacral fracture using three-dimensional reconstruction and reverse engineering technique.

Objective: To provide a new method in the fixation of sacral fracture by means of three-dimensional reconstruction and reverse engineering technique.
Methods: Pelvis 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.
Results: Accurate screw placement was confirmed with postoperative X-ray and CT scanning. The navigation template was found to be highly accurate.
Conclusion: The navigation template may be a useful method in minimal-invasive fixation of sacroiliac joint fracture.