One-Year Prospective Evaluation of the Technique of Percutaneous Cortical Bone Trajectory Spondylodesis in Comparison with Percutaneous Pedicle Screw Fixation: A Preliminary Report with Technical Note.

Background and Objective Cortical bone trajectory (CBT) spondylodesis is a novel screw fixation method in which screws are inserted through the pedicle in a caudal-medial to cephalad-lateral direction, providing a similar or more rigid spinal fixation compared with traditional pedicle screws. However, the traditional CBT technique requires invasive detaching and opening of the paraspinal muscle. In a small clinical prospective study we introduced a percutaneous CBT fixation technique by modifying the percutaneous pedicle screw (PPS) technique and evaluated the short-term outcome. Materials and Methods We enrolled 40 patients with lower back pain (LBP) and limb r;adicular pain with a diagnosis of spondylolisthesis who underwent transforaminal lumbar interbody fusion surgery. The patients were divided into two groups according to screw trajectory: the percutaneous CBT (pCBT) and the traditional PPS arms (20 patients in each). A consecutive group of 20 patients underwent traditional PPS, and the other underwent pCBT; dorsal spondylodesis was combined with transforaminal lumbar interbody fusion (TLIF) in both groups. Perioperative data such as operative time, blood loss, duration of fluoroscopy, and total incision length were investigated. Postoperative outcomes were evaluated using the visual analog scale (VAS) for LBP and leg pain at baseline, 1, 6, and 12 months. A p value < 0.05 was considered statistically significant. Results We observed no significant disadvantages in pCBT patients in perioperative and postoperative data compared with the PPS group. There were no complications. The pCBT patients showed a significantly shorter total incision length (p < 0.01) with a significantly shorter duration of fluoroscopy (p < 0.05). The postoperative VAS score was significantly improved in the pCBT group, especially 6 months after the surgery (p < 0.05). Conclusion The pCBT spondylodesis provided an outcome comparable with PPS fixation with a tendency for improvement 1 year postsurgery. This technique can be used in appropriate cases, combined with lumbar interbody fusion.