应用经关节螺钉固定在寰枢关节不稳中的生物力学研究与临床应用

目的 探讨后路经关节螺钉固定(Magerl技术)加植骨融合治疗寰枢关节不稳定的生物力学特性及其临床价值.方法 生物力学研究:取新鲜冰冻尸体标本30具,随机分成5组:完整标本组、寰枢椎不稳实验模型组、寰枢椎后路椎弓根螺钉固定组、寰枢椎经关节螺钉固定组及寰枢椎经关节螺钉联合Brooks钢丝固定组,每组各6具.标本施加±1.5N·m纯力偶矩作为加载的最大力矩,模仿前屈、后伸,左、右侧弯,左、右轴向旋转6种生理性运动,测量各种生理性运动的活动范围(ROM)和中性区(NZ)值.应用SPSS 11.0软件进行统计分析,比较组间差异.临床研究:2000年2月至2005年1月应用寰枢椎经关节螺钉(Magerl技术)固定、C1.2棘突间植骨融合术治疗寰枢椎不稳患者23例,男16例,女7例;年龄17～62岁,平均38.6岁;先天性畸形致脱位3例,外伤性脱位20例.所有患者进行定期随访和影像学检查,评估颈椎稳定性和植骨融合率.结果 标本生物力学测试结果表明:屈伸稳定性、侧弯稳定性和轴向稳定性均为寰枢椎经关节螺钉联合Brooks钢丝固定组＞寰枢椎经关节螺钉固定组＞寰枢椎椎弓根螺钉固定组＞寰枢椎完整标本组＞寰枢椎不稳模型组,组间差异有统计学意义.临床研究表明:23例共放置经关节螺钉46枚;无一例发生椎动脉损伤、脊髓损伤或舌下神经麻痹等并发症.23例患者均获随访,随访时间4～36个月,平均15个月;随访中2例患者主诉旋转活动部分受限;影像学检查提示所有患者植骨全部融合.结论 单纯的Magerl螺钉固定失稳的寰枢关节具有足够坚固的生物力学性能,临床上结合棘突间植骨可达到满意的骨性融合.

Single use of transarticular screws in atlantoaxial instability

Objective To research the biomechanical characteristics and clinical applicant of posterior transarticular screws (Magerl technique) with bene graft in atlantoaxial instability.Methods 30 fresh cadaver human cervical spine specimens were obtained and randomized subdivided into 5 groups:intact group,atlantoaxial destabilized group,atlantoaxial destabilized and fixed with pedicle screws group,fixed with Magerl screws group and fixed with Maged screws combined with Brooks way group.ROM(range of motion)and NZ(neutral zone)of extend,flex,right and left lateral bend,right and left rotation of each specimen in 5 groups were measured.Transarticular screws were placed in 23 patients with atlantoaxial instability from 2000 Feb.to 2005 Jan.,with 16 males and 7 females,age from 17 to 62 years.20 of them were traumatic dislocation and 3 were congenital instable.Results Biomechanical study indicated that stability of all 6 degrees were Magerl+Brooks＞Magerl screws＞Pedicle screws＞Intact＞Destabilized.23 patient were fixed with 46 Maged screws in total,none were suffered from vertebral artery injury and neurological deterioration.All patients were followed-up from 4 to 36 months.2 of them complained that difficult in rotation of head.Conclusion Single use of Magerl screw can provide enough biomechanical stable for adantoaxial instability,and is an effective,low-risky way combined with intra-spinal-process bone graft.