Characteristics of lower lumbar pedicle screw angle in Chinese population using digital technology / 中国组织工程研究

ABSTRACT

BACKGROUND:Pedicle screw fixation is the mainstream type of spine operation currently. The key point of the fixation is to make the screw pass through the center of pedicle. The angle of pedicle screw implantation is a key factor for repair quality. In previous literatures, angle of pedicle screw is determined according to the patient body, and is easily disturbed by factors such as position of the body. OBJECTIVE:To determine the inserting angle of pedicle screw of lower lumbar spine taking local anatomic landmark as a reference using digital technology. METHODS:3D-CT data of 100 patients were selected. The fourth and fifth lumbar vertebrae received three-dimensional reconstruction, and the operation was simulated using digital technology to achieve optimal placement. After simulation, the angle of pedicle screw was measured. The angle of the planes of the midline of the screw and the midline of the spine served as coronal angle. The angle of the planes of the midline of the screw and the upper surface of the vertebral body served as sagittal angle. RESULTS AND CONCLUSION:Measure results suggest that each angle was bigger than the angle in previous studies, which might be induced by different reference markers. Standard deviation of each angle was also big. These findings verify that the anatomical differences of pedicles were apparent. Thus, we should insert the pedicle screws individual y. Method of locating reference using anatomic landmarks of a single vertebral body can maximize to avoid interference posture. The combination with preoperative three-dimensional reconstruction is more in line with the requirements of pedicle screw, and can effectively improve the accuracy of pedicle screws.