Three-Dimensional-Printed Individualized Guiding Templates for Surgical Correction of Severe Kyphoscoliosis Secondary to Ankylosing Spondylitis: Outcomes of 9 Cases.

Abstract Objective To report the outcomes of severe kyphoscoliosis secondary to ankylosing spondylitis (AS) corrected with 3D-printing individualized guiding templates. Methods Computer tomography (CT) data of patients with severe kyphoscoliosis secondary to AS were used to reconstruct 3D models of the spine and to develop a surgical plan. An asymmetric wedge pedicle subtraction osteotomy (PSO) was simulated using medical computer design software. Before the actual surgery, continual surgical simulations were made until the most suitable one was planned, and personalized guiding templates were manufactured to the anticipatory PSO for surgery. During operation, the osteotomy plane and trajectories for the pedicle screws were positioned by the designed patient-specific 3D-printing guiding templates. Results This study reviewed 9 patients who had a correction of kyphoscoliosis using 3D-printing individualized guiding template and had been followed for 21.4 months (range, 9 months to 36 months). The average correction at the site of the osteotomy was 65.9°. There were no severe complications, such as misplacement of pedicle screws or neurologic complications, in the patients above. At the last follow-up, implant dysfunction was not observed from patients or by radiography. Conclusions By means of 3D-printing templates, preoperative surgical simulation is a viable step that enables surgical techniques to fulfill both patient- and surgeon-specific requirements for correction of severe thoracolumbar kyphoscoliosis. 3D-printing templates can guide the process of planned PSO for surgery. In summary, the 3D-printing guiding template technique brings the hope of providing good prognosis and functional restoration to the treatment of severe kyphoscoliosis secondary to AS.