Study design: A retrospective study evaluating cranial facet joint violation (FJV) by cortical bone trajectory (CBT) screw.
Objective: To determine the incidence and risk factors of FJV following CBT screw placement for different techniques.
Summary of background data: CBT is a novel technique for lumbar fusion, and FJV is one of the most common complications, leading to poor prognosis. No studies have investigated the incidence and risk factors of FJV for the CBT technique during different methods.
Methods: The authors reviewed 91 consecutive patients who underwent CBT screw instrumentation from June 2015 to August 2018. In the fluoroscopic-open group (FOG), 42 patients received an open procedure. In the navigation-open group (NOG), 24 patients underwent open instrumentation. In the navigation-percutaneous group, 25 patients underwent percutaneous instrumentation. Postoperative computed tomography scans were obtained to determine the degree and incidence of FJV. Clinical and imaging data were analyzed to clarify the risk factors of FJV.
Results: The incidence of FJV occurred in 35.7% of patients and 16.9% of screws in the FOG, 4.2% of patients and 3.8% of screws in the NOG, and 8.0% of patients and 8.0% of screws in the navigation-percutaneous group. Open instrumentation using navigation led to a lower risk of FJV compared with the conventional approach. There was no difference in the rate of FJV between percutaneous and open surgery with navigation assistance. Risk factors affecting FJV include: (1) left-side screw, facet angle ≥45 degrees, and scoliosis for fluoroscopy-assisted CBT instrumentation; (2) body mass index ≥30 kg/m, facet angle ≥45 degrees, and scoliosis for navigation-assisted CBT instrumentation.
Conclusions: Lumbar fusion through CBT instrumentation would reduce FJV. Computer-assisted navigation resulted in a lower incidence of FJV. Percutaneous instrumentation with navigation assistance is not a risk factor for FJV. Special care should be taken in patients with body mass index ≥30 kg/m, left-side screw, facet angle ≥45 degrees, and scoliosis.
Level of evidence: Level III.