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

Objective: To report the outcomes of severe kyphoscoliosis secondary to ankylosing spondylitis (AS) corrected with 3D-printed individualized guiding templates.

Methods: Computed 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 performed until the most suitable one was obtained, and personalized guiding templates were manufactured for the anticipated PSO. During operation, the osteotomy plane and trajectories for the pedicle screws were positioned by the designed patient-specific 3D-printed guiding templates.

Results: In this study, we reviewed 9 patients who underwent correction of kyphoscoliosis using a 3D-printed individualized guiding template and were followed for a median of 21.4 months (range, 9-36 months). The average correction at the site of osteotomy was 65.9°. No patient experienced severe complications, such as misplaced pedicle screws or neurologic complications. At the last follow-up, no patient exhibited implant dysfunction on radiography.

Conclusions: Preoperative surgical simulation using 3D-printed templates is a viable technique that enables surgery to meet both patient- and surgeon-specific requirements for correction of severe thoracolumbar kyphoscoliosis. These 3D-printed templates can guide the performance of planned PSO to provide functional restoration of severe kyphoscoliosis secondary to AS.