枢椎棘突螺钉与椎弓根螺钉固定的生物力学拔出力比较  

A mechanical comparison of spinous process screwing and pedicle screwing in posterior internal fixation of C2

作　　者：刘观焱[1] 徐荣明[1] 马维虎[1] 赵红勇[1] 林华杰[1] 许楠健[1] 孙韶华[1] 吕荣坤[2] 

机构地区：[1]浙江省宁波市第六医院骨科,315040 [2]浙江大学力学中心实验室

出　　处：《中华创伤骨科杂志》2012年第4期318-320,共3页Chinese Journal of Orthopaedic Trauma

基　　金：浙江省医药卫生优秀青年科技人才专项基金计划（2010QNA021）

摘　　要：目的比较枢椎棘突螺钉和椎弓根螺钉的生物力学拔出力强度。方法取8具新鲜尸体枢椎标本（C2）。于椎体两侧随机进行枢椎棘突螺钉和椎弓根螺钉固定，置入直径为4．0mm的皮质骨螺钉。枢椎棘突螺钉进钉点选择为棘突的基底部、棘突及椎板的交界处，进钉角度为水平置钉，螺钉由对侧棘突基底部穿出，形成双层皮质固定；枢椎椎弓根螺钉在直视椎弓根下置钉。置钉后行拔出强度实验，比较2种螺钉的最大轴向拔出力强度。结果枢椎棘突螺钉的平均拔出力度为（387．56±0．862，P=0．403）；枢椎棘突螺钉的平均钉道长度为（21．42±1．14）mm，稍短于枢椎椎弓根螺钉的（23．16±1．01）mm，差异有统计学意义（t=4．368，P〈0．05）。结论枢椎棘突螺钉具有椎弓根螺钉相近的生物力学拔出力强度，枢椎棘突螺钉在生物力学上具有应用可行性。Objective To eompare the pedicle screwing in posterior internal fixation of C2 pullout strength between spinous process screwing and Methods Eight fresh human cadaveric C2 were harvested. Spinoas process screws were placed on one side of the C2 and pedicle screws were placed on the other side in a random manner. Cortical bone screws of 4. 0 mm in diameter were used. The starting point for spinous process screw insertion was located at the junction of the lamina and the spinous process and the direction of the screw was about 0°caudally in the sagittal plane and about 0° medially in the axial plane. Pedicle screws were placed under direct visualization. After screw placement, each set of vertebral bodies were mounted in a custom jig for axial pullout testing using a servo-hydraulic testing machine. The loadisplacenmnt curves were obtained for each screw pullout. Results The mean pullout strength for the spinous process screws was 387.56 ± 137.73 N, not significantly different from that for the pedicle screws （465.25 ±214.32 N） （ t = -0. 862, P = 0. 403）. The working length for the spinous process screws （21.42 ±1. 14 mm） was significantly shorter than for the pedicle screws （23. 16 ± 1. Ol ram） （ t = 4. 368, P 〈 O. 001 ）. Conclusion Since spinous process serews have similar pullout strength as compared with pedicle screws, they are biomechanically feasible in clinical application.

关 键 词：枢椎 生物力学 内固定器 螺钉 

分 类 号：R684.705[医药卫生—骨科学]