摘要
目的：利用Unigraphics（UG）三维重建技术寻找枢椎侧弓螺钉安全钉道的经过，并进行相关参数的测量。方法：对4例干燥和8例新鲜枢椎行CT扫描，UG软件重建虚拟实体，利用3.5mm虚拟螺钉模拟进钉，寻找安全钉道经过的特征标记点。以此为基础，测定57例干燥枢椎安全钉道的内倾角与上倾角（AutoCAD环境）及进针点距峡部及下关节突外缘的距离（手工测量）。结果：模拟发现横断面安全钉道经过前弓中宽后界的内中1／3交界与中宽前界的外中1／3交界,矢状面经过前弓中宽后界中部及前界中宽与上关节突下界交界处。对另57例干燥标本进行测量发现安全钉道的内倾角为左／右=（10.94±6.53）°／（11.95±2.82）°，上倾角为（13.31±5.44）°／（14.45±3°80）°,在大多数标本椎板后下方有一突起的骨嵴（左／右=84.2％／84.98％），进针点多位于这一骨嵴线上（左／右=87.5％／84.9％）。进针点距离下关节外侧缘左／右=（6．71±1.33）mm／（6.28±1.48）mm，距离后弓左／右=（9.93±1.38）mm／（8.47±1.70）mm。个体间差异较大。结论：侧方椎弓螺钉固定的安全钉道在横断面经过横突孔区域（侧弓前份）中宽后界的内中1／3交界与中宽前界的外中1／3交界，矢状面经过后方中宽中部及前方中宽与关节突下界交界处，不同侧别间及不同个体间有明显差别。
Objective：To search and measure medial and superior inclination of safe screw trajectory of axis＇lateral arch with the help of computer stimulated method based on 3-D reconstructive axes and screw models. Methods：Imaginary axes were reconstructed in Unigraphics software based on the consecutive CT scanning images of 4 dry and 8 fresh axes. A 3.5 mm-diameter imaginary cortical screw was then introduced to penetrate into the medullary cavity of axis＇lateral arch to find out the characteristic points of safe trajectory, based on which, 57 dry real axes＇safe screw trajectories were determined and their medial and superior inclinations and relative linear data were measured. Results：The simulating axes in UG showed that the safe trajectory on horizontal plane passed through the intersection of medial-median division of posterior boundary of median portion （MP） of anterior lateral arch （distinguished from posterior lateral arch by posterior tubercle of transverse foramen） and intersection of median-lateral division of anterior boundary of MP, and on sagittal plane passes through the median position of posterior boundary of MP and inferior edge of superior process. The safe medial and superior inclinations of the safe trajectories on other 57 dry real axes （x ± s, Left/right ） were （10.94±6.53）°/（11.95 ±2.82）° and （13.31 ±5.44）°/（14.45 ±3.80）° ,respectively. In most cases （ L/R = 84.2%/84.98% ） there was a distinct protruded bone ridge at each side of inferior region of lamina and screw entrance point was more likely to locate at the ridge line （I_/R = 87.5%/84. 9% ）. The distance（x ± s,Left/right ） from entrance point to lateral edge of inferior articular process and to anterosuperior boundary of isthmus are （6.71± 1.33 ） mm/（ 6.28 ±1.48 ）mm and （ 9.93 ± 1.38 ） mm/ （8.47± 1.70）mm respectively . There were noticeable interindividual variations in parameter values. Conclusions-The safe trajectory of axis＇lateral arch screw passes through the intersection of medial-median division of posterior boundary of MP and that of median-lateral division of anterior boundary of MP from axial view, and through the median position of posterior boundary of MP and inferior edge of superior process from lateral view. Safe screw trajectory should be determined individually, as obvious parameter difference exists between individuals and between different sides of the same individual.
出处
《解剖与临床》
2007年第5期296-299,共4页
Anatomy and Clinics
关键词
枢椎
侧方椎弓
安全钉道
三维重建
解剖
Axis
Lateral arch
Screw safe trajectory
3-D reconstruction model
Anatomy
