Comparison of Cortical Bone Trajectory to Pedicle-Based Dynamic Stabilization: An Analysis of 291 Patients

Abstract

Objective: Pedicle-based dynamic stabilization (DS) has gained popularity outside of Ameri-ca. Although pedicle screw (PS) loosening has always been a concern, it is reportedly in-nocuous. Cortical bone trajectory (CBT) screw is an emerging option with less invasiveness and similar effectiveness to PS in short-segment lumbar fusion. This study aimed to verify the use of CBT for DS by comparing the outcomes between pedicle-and CBT-based DS. Methods: Consecutive patients with lumbar spondylosis or low-grade spondylolisthesis who underwent 1-or 2-level DS between L3–5 with a minimum follow-up of 24 months were reviewed. Screw loosening was determined by computed tomography and the inci-dences were compared. Results: A total of 291 patients who underwent Dynesys DS (235 pedicle-and 56 CBT-based, respectively) were compared. The demographics and preoperative conditions were similar. All the clinical outcomes improved at 24-month postoperation, while the CBT-based group had less operation time and blood loss than the pedicle-based group. The rates of screw loosening were lower in the CBT-based (5. 4% per screw and 12. 5% per patient) than the pedicle-based group (9% per screw and 26. 4% per patient). Furthermore, there were no differences in the clinical outcomes and complication profiles. Conclusion: The CBT-based DS for 1-or 2-level lumbar degeneration demonstrated equiv-alent clinical improvement as the pedicle-based DS. The adaption of CBT-based screws for DS could be a less invasive approach (shorter operation time and less blood loss), with lower chances of screw loosening than the conventional PS-based DS.