CT multiple-level reconstruction for preoperational estimation of facet joint violation in lumbar percutaneous pedicle screw placement / 中国组织工程研究

ABSTRACT

BACKGROUND: Percutanoues pedicle screw internal fixation is widely used for treating lumbar disease. Because the surgery is guided by the C-arm, it is hard to control the position between screws and facet joint to cause the facet joint violation completely. Body mass index > 29.9 kg/m2, facet joint angle > 35°and age < 65 years old are considered as the high risk factors for percutaneous pedicle screw injury of articular processes. Due to the different positional relationship between the pedicle axis of the lumbar spine and the articular process joint, there is no related report on whether the destruction of the articular process joint by screws is different. OBJECTIVE: To investigate the significance of lumbar CT multi-planar reconstruction for preestimating facet joint violation in lumbar percutaneous pedicle screw placement. METHODS: One hundred patients with lumbar fracture and degenerative disease who underwent percutaneous pedicle screw placement were selected. All patients signed the informed consents and the study was approved by the ethics committee of the hospital. The position line of the oblique axial view, oblique sagittal view and oblique coronal view was adjusted to reconstruct the section of pedicle. A circle with the 6.5 mm of position line of the oblique coronal view as its center to check the relationship between the circle and facet joint served as preoperation group. CT examination was performed after surgery for evaluating the degree of facet joint violation by screws and served as postoperation group. The amount of screws which damage the facet joint of different vertebrae between two groups and the damage rate among vertebrae in each group were compared. RESULTS AND CONCLUSION: (1) Totally 478 screws were placed, 109 (22.8%) screws violated facet joints in the preoperation group, and the amount of circles which violated facet joint was 6 (6.8%), 9 (10.5%), 19 (18.3%), 30 (30.0%), and 45 (45.0%) from L1-L 5. (2) 115 (24.1%) screws violated facet joints in the postoperation group, the amount of circles which violated facet joint was 10 (11.4%), 7 (8.1%), 15 (14.4%), 26 (26.0%) and 41 (41.0%) from L1-L 5. (3) The P values of McNamara test of different vertebrae were 0.08 (L1), 0.22 (L2), 0.20 (L3), 0.05 (L4) and 0.08 (L5). There was no significant difference between two groups. (4) The results of Kappa test were 0.67 (L1), 0.80 (L2), 0.80 (L3), 0.87 (L4) and 0.92 (L5). The damage rate among vertebrae in each group had significant differences (P=0.000). (5) To conclude, the relationship between percutanoues pedicle screw and facet joint could be recognized by lumbar CT multiple level reconstruction, which provides a reliable method for preestimating the possibility of facet joint damage caused by the percutanoues pedicle screw.