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

Abstract

Revision surgery for adjacent segment degeneration (ASD) commonly requires exposing and removing the original fixation. To minimize trauma and to reduce the operation time and blood loss, we introduced 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 surgical data, including the operation time, blood loss, and incision length, were recorded. We evaluated the clinical efficacy using the visual analog 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 screw fixation, the accuracy of screws, and the fusion rate. Results: The mean follow-up was 22.4±4.7 months (12-31 months). The VAS, ODI, and JOA scores were analyzed by SPSS 21.0 and showed significant improvement at 2 weeks and the last follow-up compared with preoperative data (P<0.05). Seventy-six CBT screws were inserted with navigation templates; 2 screws were Grade B, and the other screws were Grade 0 or A. Changes in intervertebral height showed good stability of CBT screw fixation (P>0.05). All the patients exhibited satisfactory fusion results. Conclusion: Revision surgery for ASD with CBT screws assisted by 3D-printed navigation templates has satisfactory clinical efficacy with the advantages of a short operation time, a small incision, and less blood loss.

Clinical applications and prospects of 3D printing guide templates in orthopaedics

“… 2021 He K et al. [ 100 ] Clin Interv Aging 18 CBT screws for revision surgery of ASD Revision surgery for ASD with CBT screws assisted by 3D-printed navigation templates has satisfactory clinical efficacy with the advantages of a short operation time, a small incision, and less blood loss. 2020 Matsukawa K et al.…”

“…[ 97 ]. Subsequently, an increasing number of authors have reported the use of guides in lumbar screw placement [ [98] , [99] , [100] ]. It offers a similar effect in the cadaveric study.…”

Comparative effectiveness of cortical bone trajectory screws and pedicle screws in the treatment of adjacent segment degeneration after lumbar fusion surgery: a systematic review and meta-analysis

“…The rate of screw loosening may increase if the original trajectory is reinserted using the same instrumentation as in the initial surgery [ 32 , 33 ]. The course of the disease from the initial lumbar fusion to ASD is generally very long, and the bone quality of such patients is decreased to varying degrees.…”