Feasibility of two kinds of atlantal lateral mass screw fixation / 中国组织工程研究

ABSTRACT

BACKGROUND:Atlantal lateral mass screw fixation contains lateral mass screw fixation under the posterior arch of the atlas and lateral mass screw fixation via the posterior arch of atlas (also cal ed atlas pedicle screw fixation) according to different insertion points. The two methods have their advantages and disadvantages. There are lacks of the comparative studies on bony anatomy feasibility by two kinds of atlantal lateral mass screw fixation. OBJECTIVE:To compare the feasibility associated with two kinds of atlantal lateral mass screw fixations taking Chinese data of atlantal bony anatomy as evidence. METHODS:Data of CT scans in 30 adults with cervical spondylosis (60 sides) were col ected, and data were reconstructed using CT workstation. We measured key bone anatomy structure after atlantal lateral mass screw fixation. The atlantal lateral mass was suitable for lateral mass screw fixation via the posterior arch of atlas if its height and width of vertebral artery groove at the posterior arch ≥ 4 mm. It was suitable for lateral mass screw fixation under the posterior arch of the atlas if the height of posterior arch of atlas lateral mass ≥ 4 mm. RESULTS AND CONCLUSION:The height of vertebral artery groove at the posterior arch was (4.54±1.17) mm. The width of vertebral artery groove at the posterior arch was (8.69±1.12) mm. The height of posterior arch of atlas lateral mass was (4.98±1.07) mm. There were 41 cases with the height of vertebral artery groove at the posterior arch>4 mm (suitable for lateral mass screw fixation via the posterior arch of atlas, occupying 68%. There were 52 cases with the height of posterior arch of atlas lateral mass>4 mm (suitable for lateral mass screw fixation under the posterior arch of the atlas), occupying 87%. There were significant differences in the differences between the two groups (P<0.05). These results indicated that lateral mass screw fixation under the posterior arch of the atlas was more feasible compared with lateral mass screw fixation via the posterior arch of atlas. Preoperative CT measure for key anatomic structure was significant for making personalized surgical plan.