后路枕骨髁螺钉通道的影像解剖学研究

摘要

Objective To investigate the optimal trajectory of posterior occipital condyle screw fixation via radiological and anatomical study.Methods Twelve adult craniocervical junction complete specimens were selected.The length,width and height of occipital condyle and the inclination angle of the longest axis were measured by CT scanning and reconstruction.Subsequently,occipital condyle screws were inserted with reference to CT measurements.After screw fixation,accuracy and safety of the placement of occipital condyle screw were verified by gross observation and CT scanning.Results Preoperative measurements of height and width of the occipital condyles indicated the placement of 4.0 mm bicortical screws was secure.Left vertebral artery horizontal sections of 2 specimens were slightly pressed without damage.CT scanning identified no damage to the inner or outer wall of the occipital condyle and the hypoglossal canal.Trajectory parameters between the right and left sides were slightly different,but no significant difference was observed (P ＞ 0.05).Average screw channel length and inclination angle were (20.8 ±2.6)mm and (37.1 ± 4.7)°respectively.Angle between screw and skull base tangent was observed as (8.5 ± 1.7) °.Distance between screw axis and hypoglossal canal was observed as (3.1 ± 1.1) mm.And the distance averaged (4.6 ± 1.4) mm between occipital condyle screw entry point and skull base and (6.1 ± 1.5) mm between entry point and inside edge of the occipital condyle.Conclusion Occipital condyle can be used as a new alternative fixed point in occipitocervical fusion.%目的 通过影像解剖学研究探讨国人后路经枕骨髁螺钉固定的最佳置钉参数.方法 通过随机抽样选取12具成人枕颈部尸体标本,CT扫描测量枕骨髁的长度、宽度,舌下神经管下缘至枕骨髁下缘的垂直距离,在枕骨髁中轴面、矢状面上测量最长轴线与正中矢状面的夹角和与颅底切线的夹角等,然后根据测量结果指导置钉,通过大体观察和影像学验证置钉准确性及安全性.结果 术前枕骨髁高度、宽度的测量结果提示适合置入直径为4.0 mm双皮质螺钉.术后发现2具标本左侧椎动脉水平段有轻微压迫,无破损.CT扫描验证未发现枕骨髁内、外侧壁及舌下神经管破损.左、右侧枕骨髁钉道参数的测量结果稍有差异,但差异无统计学意义(P＞0.05).钉道长度为(20.8 ±2.6)mm,内倾角为(37.1±4.7)°,与颅底切线的夹角为(8.5±1.7)°,螺钉轴线至舌下神经管下缘的距离为(3.1±1.1)mm,进钉点至颅底的垂直距离为(4.6±1.4)mm,至枕骨髁内侧缘的水平距离为(6.1±1.5)mm.结论 枕骨髁螺钉技术同样可应用在国人身上,并初步测量出其置钉参数.