A Minimally Invasive Technique Using Cortical Bone Trajectory Screws Assisted by 3D-Printed Navigation Templates in Lumbar Adjacent Segment Degeneration

Abstract Background: Revision surgery of adjacent segment degeneration (ASD) commonly need to expose and remove the original fixation. In order to minimize the trauma, reduce the operation time and blood loss, we introduce a minimally invasive lumbar revision technique using cortical bone trajectory (CBT) screws assisted by three-dimensional(3D) printed navigation templates.Methods: From April 2017 to October 2019, 18 patients with ASD underwent revision surgery with CBT screws assisted by 3D-printed templates in our hospital. All the operation data, including operation time, blood loss, incision length were recorded. We evaluated the clinical efficacy using the visual analogue scale (VAS), the Oswestry Disability Index (ODI), and the Japanese Orthopedic Association (JOA) score. X-ray and Computed Tomography (CT) scans were used to evaluate the stability of CBT screws fixation, the accuracy of screws, and the fusion rate.Results: The mean follow-up was 22.4±4.7 months (12-31m), the VAS, ODI, and JOA score were analyzed by SPSS 21.0 and showed significant improvement at 2-weeks and the last follow-up compared with preoperative data(P0.05). All the patients had satisfactory fusion results.Conclusion: Revision surgery of ASD with CBT screws assisted by 3D-printed navigation templates has satisfactory clinical efficacy with advantages of the short operation time, small incision, and less blood loss.