摘要
目的 :研制应用于齿状突Ⅱ骨折前路内固定的新型抗旋转中空脊状钛螺钉 ,并进行生物力学研究。方法 :将 12个头颈椎复合体 (C0 ～C3 )随机分为 3组 :脊状螺钉组 ,双螺纹螺钉组及双螺钉组 ,分别测量各组正常时、齿状突Ⅱ骨折复制后、螺钉内固定后及 60 0 0次循环加载疲劳试验后各状态下的C0 ～C2 节段各运动方向的总刚度。结果 :齿状突骨折后 ,C0 ～C2 节段各运动方向的总刚度均显著下降 ;3种螺钉内固定后提供的各运动方向的瞬时总刚度 (除脊状螺钉组前屈运动方向外 )均显著小于正常状态下相应运动方向的刚度。各组间瞬时总刚度比较 :脊状螺钉组及双螺纹螺钉组旋转刚度显著大于双螺钉固定组。各组间疲劳试验后总刚度比较 :脊状螺钉组的屈伸、侧弯运动刚度均大于其他两组 ;脊状螺钉组的旋转运动刚度显著大于双螺钉组 ,而双螺纹螺钉组与双螺钉组无显著差别。结论 :脊状螺钉优于其他类型的螺钉 ,尤其表现在抗旋转及抗疲劳能力上。
Objective: To devise a 6.0mm cannulated long finned compressive screw and study the biomechanical characteristics to assess the effectiveness in restoring spinal stability of Type Ⅱ odontoid fracture.Methods:12 human cadaveric spines(C 0～C 2) were divided into three groups:long finned screw group;two 3.5mm AO screws group;a single 4.5mm Double threaded screws group.After testing nondestructive flexion,extension,lateral bending,and torsion of intact specimens,they were also tested immediately after osteotomy,after direct internal fixation with screws,and after 6000 cycles of fatigue stress test.The slope of the load versus deformation curve determined the stiffness values of C 0～C 2.Results:The stiffness values of specimens were all decreased after osteotomy and were not restored completely after using screws fixation.The stiffness values especially torsional values of long finned screw group were grater than other two groups before and after 6000 cycles of fatigue.It were true that the stiffness values of the Double threaded screws group were also greater than the two screws group before fatigue;but their values were similar after fatigue.Conclusion:The cervical spine fixing by a new devised screw is biomechanically more stable than by other fixations
出处
《中国矫形外科杂志》
CAS
CSCD
2002年第10期992-995,共4页
Orthopedic Journal of China
