下颈椎前路椎弓根螺钉配套钢板系统的生物力学性能研究

Biomechanical characteristics of anterior pedicle screw-plate system in the lower cervical spine

目的 探讨下颈椎前路椎弓根螺钉配套钢板系统在颈椎病患者的生物力学性能.方法 采集新鲜颈椎标本16具,分解为C3/4、C4/5、C5/6、C6/7共32个运动节段（FSU）,其中C3/4、C4/5、C5/6、C6/7各8个.将其按照不同节段随机分成A、B两组,将所获标本椎间盘切除后模拟植骨、分别植入我们自行设计生产的下颈椎前路椎弓根螺钉配套钢板系统和普通颈椎前路椎体螺钉钢板系统,比较两组固定系统的生物力学性能：（1）两组下颈椎三维生理运动范围（ROM）;（2）两组稳定性指数;（3）两组螺钉的抗拔出力.结果 A、B两组各有16个FSU（其中C3/4、C4/5、C5/6、C6/7节段各4个）,A组植入下颈椎前路椎弓根螺钉配套钢板系统16套,B组植入普通颈椎前路椎体螺钉钢板系统16套.经生物力学测试发现：（1）A组固定的颈椎节段前屈/后伸平均运动值为（12.78±1.32）°,左右侧弯（9.25±0.94）°,左右旋转（22.82 ±2.42）°;而B组分别为（16.24±1.64）、（12.08±1.32）、（28.44± 2.78）°.A组优于B组,差异有统计学意义（P＜0.05）.（2）A组稳定性指数（Sf）在屈伸、侧屈、旋转时分别为111％、110％、112％,而B组分别为87％、84％和88％,两者比较差异有统计学意义（P＜0.05）.（3）抗拔出力测试结果显示,A组最大抗拔出力为（604.68±48.76）N,而B组为（488.24±32.42）N,A组优于B组,两者比较差异有统计学意义（P＜0.05）.结论 下颈椎前路椎弓根螺钉配套钢板系统在生物力学性能方面优于普通颈椎前路椎体螺钉钢板系统,适用于需要颈椎前路坚强固定的患者.

Objective To explore the biomechanical characteristics of anterior pedicle screw-plate system in the lower cervical spine,and to provide basic data for clinical application.Methods Sixteen fresh cervical cadavers were collected and dissected into 32 different FSUs （8 separately in C3/4,C4/5,C5/6,and C6/7）.After disectomy and intervertebral body bone graft,the subjects were randomly divided into group A and group B.The anterior cervical pedicle screw-plate system and anterior vertebral body screw-plate system were implanted separately in the group A and group B.The biomechanical characteristics were compared between group A and group B,incuding range of motion （ROM）,stability potential index （Sf） and pullout strength.SPSS 13.0 was used and P 〈 0.05 was considered as significant difference.Results There were 16 FSUs separated in group A and group B （each four in C3/4,C4/5,C5/6 and C6/7）.Sixteen anterior cervical pedicle screw-plate systems were implanted smoothly in group A,and sixteen anterior vertebral body screw-plate systems in group B.The average flexion/extension ROM was （12.78 ± 1.32） °,lateral bending （9.25 ± 0.94） ° and axial rotation （22.82 ± 2.42） ° in group A,and （16.24 ± 1.64） °,（12.08 ± 1.32） °,（28.44 ± 2.78） ° respectively in group B.There was significant difference between the two groups （P 〈 0.05）.Sf was 111% （flexion/extension）,110% （lateral bending）,112% （axial rotation） in group A,and 87%,84% and 88% respectively in group B.The difference was significant （P 〈 0.05）.The greatest pullout strength was （604.68 ± 48.76） N in group A and （488.24 ± 32.42） N in group B respectively （P 〈 0.05）.Conclusion The biomechanical characteristics of anterior cervical pedicle screw-plate system are better than those of vertebral body screw-plate system.The anterior cervical pedicle screw-plate system can be used for patients who need strong anterior cervical construction.