不同后路短节段内固定术治疗Hangman骨折的生物力学比较

Biomechanical study of different posterior cervical oligo-segmental fixation for the treatment of Hangman's fracture

目的:测试不同后路短节段内固定术治疗Hangman骨折的生物力学性能,探讨内固定方式的选择。方法:8具新鲜C0～C4颈椎标本,按照①正常状态(对照组);②Ⅰ型骨折C2椎弓根螺钉固定(A组);③ⅡA型骨折C2椎弓根螺钉固定(B组);④Ⅱ型骨折C2椎弓根螺钉固定(C组);⑤Ⅲ型骨折C2椎弓根螺钉固定(D组);⑥Ⅲ型骨折C2、3椎弓根侧块钢板内固定(E组)顺序在脊柱三维运动实验机上依次测试其三维运动范围(ROM),对结果进行统计学分析。结果:A组ROM值与对照组无显著性差异;B组除旋转外与对照组无显著性差异,旋转稳定性也达到了对照组的61.86%;C组与对照组均有显著性差异;D组ROM值最大,与对照组有显著性差异;E组除后伸外ROM值均明显小于对照组,差异有显著性(P<0.05)。结论:C2椎弓根螺钉固定可使Ⅰ型Hangman骨折达到生理性固定,使ⅡA型骨折恢复较好的稳定性,不能使Ⅱ、Ⅲ型骨折获得稳定;后路C2、3椎弓根侧块钢板内固定后的三维稳定性较好,适合不稳定型Hangman骨折的外科治疗。

Objective：To Evaluate the biomechanical stability and investigate the choice of posterior cervical oligo-segmental fixation for the treatment of Hangman＇s fracture.Method：Eight fresh adult human cervical specimen were designed to conduct the research of three-dimensional motion stability.All specimen were divided into seven groups：（1）intact control（control group）,（2）transpedicle screw fixation in Type Ⅰ fracture（group A）, （3）transpedicle screw fixation in type Ⅱ A fracture （group B）, （4）transpedicle screw fixation in type Ⅱ fracture（group C）,（5）transpedicle screw fixation in type Ⅲ fracture（group D）,（6）C2.3 pedicular-lateral mass plate fixation in type Ⅲ fracture（group E）.Range of motion（ROM） was test.The result were put into statistical procedure.Result：The ROM of group A had no significant difference with that of the control group.The ROM of group B had no significant difference with that of the control group except rotation,each ROM of group C and group D was significant difference with the control group,and the ROM of group D was the biggest.The ROM of group E was the smallest and had statistically significant difference in each motion compared with the control.Conclusion：Type Ⅰ fracture can get physiological stability after transpedicle screw fixation,type Ⅱ A fracture can get good stability and be available to transpedicle screw fixation,but type Ⅱ.Ⅲ fracture isn＇t suited for transpedicle screw fixation alone.C2、3 pedicular-lateral mass plate has excellent biomechanical performance for the treatment of unstable Hangman＇s fracture.