摘要
背景:现有的胸椎椎弓根置钉内固定技术均以上关节突或联合横突为参考标志确定进钉点,以假想的横断面和矢状面为参考标志确定进钉角度,诸位学者描述不一。由于患者术中体位的影响和术者主观判断的偏差,易出现螺钉误置,产生严重并发症,限制了该技术的临床应用和推广。目前,临床上选择一个单一的不受患者体位影响且容易判断的骨性标志作为胸椎椎弓根置钉进钉点和进钉角度的参考,显得尤为重要。目的:通过三维重建CT图像的测量探讨正常成人胸椎以上关节突作为单一解剖标志确定椎弓根置钉参数的可行性及其具体的对应关系。方法:选取30例正常成人胸椎CT图像进行三维重建,在重建后的T1-T12特定CT图像上直接测量以下参数:(1)基础参数:包括进钉点至中线距离、上关节突外缘至中线距离和上关节突基底宽度。通过基础参数间接计算进钉点参数,包括横向点突距、进钉点比率和纵向点突距,即进钉点至上关节突外缘的水平距离及其与上关节突基底宽度的比率和进钉点至上关节突基底的垂直距离;(2)进钉角度参数:横向轴突角和纵向轴突角,即横断面和矢状面上椎弓根轴线与上关节突关节面的夹角;(3)进钉深度参数:螺钉安全长度,即椎弓根轴线上进钉点至椎体前缘骨皮质的距离。统计每组参数的平均值和标准差,并比较各节段统计数据的差异。结果与结论:(1)利用三维重建CT技术,可以成功获取T1-T12经双侧椎弓根轴线横断面、经上关节突基底且平行于双侧椎弓根轴线的横断面和经单侧椎弓根轴线斜矢状面的图像;(2)基础参数:T1-T12左右两侧进钉点至中线距离分别为(14.6±2.6)mm和(14.5±2.5)mm,上关节突外缘至中线距离分别为(15.7±1.9)mm和(15.7±2.0)mm,上关节突基底宽度分别为(8.8±1.3)mm和(8.8±1.1)mm。每一参数左右两侧测量值差异无显著性意义(P=0.343,0.214,0.467);(3)置钉参数:T1-T12左右两侧横向点突距分别为(1.2±1.3)mm和(1.3±1.4)mm,进钉点比率分别为(14.3±17.0)%和(13.6±16.1)%,纵向点突距分别为(3.4±0.8)mm和(3.3±0.9)mm,横向轴突角分别为(92.4±4.7)°和(92.6±5.0)°,纵向轴突角分别为(91.8±4.1)°和(91.7±3.6)°,螺钉安全长度分别为(40.7±4.8)mm和(40.4±4.6)mm。以上每一参数左右两侧测量值差异无显著性意义(P=0.073,0.084,0.310,0.265,0.241,0.175);(4)以上结果提示,正常成人胸椎以上关节突作为单一解剖标志确定椎弓根置钉参数简单可行,前者与后两者存在特定的对应关系,可作为一种新的临床上选择置钉参数的方法。
BACKGROUND： In the existing thoracic pedicle screw fixation technique, superior facet or combined with transverse process and the imaginary transverse and sagittal section are used as the reference mark of pedicle screw entry point and angle, respectively, which still remain controversial. Because of the effect of position deviation and subjective judgment during surgery, screw misplacement and severe complications often occur, which limit the clinical application and promotion of the technique. At present, it is very important to select a single bony mark, which is not affected by the patient＆#39;s position, and is easy to judge, as the reference mark of screw entry point and angle. OBJECTIVE： To explore the feasibility of taking superior facet as a single bony mark to determine thoracic pedicle screw parameters in normal adults by measuring 3D reconstruction CT image and it＆#39;s corresponding relationships. METHODS： 3D reconstruction CT images of the thoracic spine in 30 normal adults were selected and the basic parameters, entry angle parameters and entry depth parameters were directly determined on specific reconstructed CT images of T1-T12.The basic parameters included the vertical distance from the entry point to the midline, the vertical distance from the outer edge of superior facet to the midline and superior facet base width. Entry point parameters were indirectly calculated by the basic parameters, including transversal point-facet distance, entry point ratio and sagittal point-facet distance, which was the horizontal distance from entry point to outer edge of superior facet, the ratio of transversal point-facet distance to superior facet base width, and the longitudinal distance from entry point to the base of superior facet. Entry angle parameters included transversal axis-facet angle and sagittal axis-facet angle, which is the transversal and sagittal angle between the axis of pedicle and the surface of facet. Entry depth parameter included safety screw length, which is the distance from entry point to anterior vertebral cortex along the axis of pedicle. Mean and standard deviation were counted and statistics difference was compared. RESULTS AND CONCLUSION： （1） Using CT technology of 3D reconstruction, T1-T12thoracic transversal section through bilateral pedicle axis, transversal section through the base of the superior facet, which parallel to the bilateral pedicle axis, and oblique sagittal section through homolateral pedicle axis were successfully obtained. （2） The statistical results of the basic parameters were as follows： the left and right vertical distances between T1-T12from the entry point to the midline were （14.6±2.6） and （14.5±2.5） mm, the vertical distance from the outer edge of superior facet to the midline were （15.7±1.9） and （15.7±2.0） mm, and superior facet base width were （8.8±1.3） mm and （8.8±1.1） mm, respectively. There was no significant difference in the measured values between two sides of the above parameters （P=0.343, 0.214, 0.467）. （3） The statistical results of pedicle screw parameters were as follows： the left and right transversal point-facet distance between T1-T12were （1.2±1.3） and （1.3±1.4） mm, entry point ratio were （14.3±17.0）% and （13.6±16.1）%, sagittal point-facet distance were （3.4±0.8） and （3.3±0.9） mm, transversal axis-facet angle were （92.4±4.7）° and （92.6±5.0）°, sagittal axis-facet angle were （91.8±4.1）° and （91.7±3.6）°, and safe screw length were （40.7±4.8） and （40.4±4.6） mm, respectively. There was no significant difference in the measured values between two sides of the above parameters （P=0.073, 0.084, 0.310, 0.265, 0.241, 0.175）. （4） These results indicate that taking thoracic superior facet as a single anatomic landmark to determine pedicle screw parameters is simple and feasible in normal adults, and they correlate with each other, which can be used as a new method for choosing screw parameters.
出处
《中国组织工程研究》
CAS
北大核心
2017年第35期5622-5629,共8页
Chinese Journal of Tissue Engineering Research
基金
衡阳市科学技术发展计划(2016KJ45)~~
