Safety and Efficacy of Cortical Bone Trajectory Screw Fixation Combined with Facet Fusion for the Treatment of Lumbar Degenerative Disease

Abstract

Objective: The mainstream lumbar fusion surgeries have various shortcomings, such as complex operation, much invasion, and loss of lumbar function. How to minimize the surgical injury and to achieve better therapeutic effects has become the goal pursued by spine surgeons. This study introduces a cortical bone trajectory (CBT) screw fixation combined with facet fusion (FF), evaluates its safety and efficacy, and explores its advantages, in order to provide a reference for treatment of patients with single-level lumbar stenosis or grade I degenerative spondylolisthesis.

Methods: We retrospectively analyzed the clinical, radiological, and operative data of 167 patients with single-level lumbar stenosis or grade I degenerative spondylolisthesis who underwent FF or transforaminal lumbar interbody fusion (TLIF) from January 2013 to September 2019 in the spine surgery department of the Second Hospital of Shandong University. Patients were divided into four groups according to surgical method: group CBT-FF, CBT screw combined with FF; group PS-FF, pedicle screw (PS) combined with FF; group CBT-TLIF, CBT screw combined with TLIF; and group PS-TLIF, PS combined with TLIF. The operation time, estimated intraoperative blood loss, complications after surgery, visual analog scale (VAS), and Oswestry disability index (ODI) of the four groups were compared. The fusion was evaluated by anteroposterior and lateral X-ray, CT scan, and three-dimensional reconstruction.

Results: Twelve months after surgery, the fusion rate of four groups had no significantly statistical differences (p = 0.914). VAS and ODI scores were lower after surgery than before. Low back pain VAS scores 1 week after surgery in group CBT-FF and group CBT-TLIF were significantly lower than those in group PS-FF and group PS-TLIF (p_CF/PF = 0.001, p_CF/PT = 0.000, p_PF/CT = 0.049, p_CT/PT = 0.000). Low back pain VAS score 3 months after surgery was significantly lower in group CBT-FF than group PS-FF and group PS-TLIF (p_CF/PF = 0.045, p_CF/PT = 0.008). ODI score 1 week after surgery was significantly lower in group CBT-FF than group PS-FF, group CBT-TLIF, and group PS-TLIF (p_CF/PF = 0.000, p_CF/CT = 0.005, p_CF/PT = 0.000, p_CT/PT = 0.015). ODI score 3 months after surgery was significantly lower in group CBT-FF than group PS-FF, group CBT-TLIF, and group PS-TLIF (p_CF/PF = 0.001, p_CF/CT = 0.002, p_CF/PT = 0.000). Incidence of complications did not significantly differ among the groups.

Conclusion: CBT screw fixation combined with FF is a safe and efficacious procedure for patients with single-level lumbar stenosis or grade I degenerative spondylolisthesis. This minimally invasive approach of lumbar fusion can be simply and easily performed. Patients who undergo CBT screw fixation combined with FF recovered faster than TLIF.

Keywords: Cortical Bone Trajectory Screw; Facet Fusion; Lumbar Degenerative Disorders; Pedicle Screw; Transforaminal Lumbar Interbody Fusion.

Fig. 1

Intra‐operative images of the CBT screw combined with FF surgery. (A) A V‐shaped notch was created in the lumbar facet joints using a bur. (B) Cortical bone trajectory screws were implanted. (C) Autogenous cancellous bone chips were packed into the notch. (D) Pre‐bent rods were placed to join the screws and tightened to each screw using a cap.

Fig. 2

Preoperative and postoperative images of a typical case. A 50‐year‐old woman was admitted to the hospital because of a 6‐month history of low back and bilateral buttock pain. She was diagnosed with lumbar spinal stenosis combined with L4‐5 spondylolisthesis and underwent L4‐5 decompression and bilateral facet joint fusion with cortical bone trajectory screw fixation. One year after surgery, computed tomography (CT) showed continuous bone bridging across the L4‐5 facet joints on both sides. (A) Preoperative dynamic lateral lumbar plain radiography. (B, C) Sagittal preoperative CT images, left and right, respectively. (D, E) Sagittal CT images 12 months after surgery, left and right, respectively. (F, G) Coronal CT images before and 12 months after surgery, respectively. (H, I) Axial CT images before and 12 months after surgery, respectively.