后柱重建术防止Dick钉断裂的生物力学研究

A biomechanical study on reconstruction of the posterior column of the spine for the prevention of Dick-screw breaking

目的 通过生物力学试验 ,证实后柱重建术对防止Dick钉断裂的意义。方法 将三种不同类型的Dick钉内固定在猪脊柱骨折模型及一组正常猪脊柱模型上 ,并放在对向挤压机上进行对向挤压后 ,测定椎体间距离变化情况 ,以正常猪脊柱模型作为正常生理标准组与其他三组进行对照。结果 在一万次对向挤压后 ,三柱损伤组的椎体间距离变化明显 (P <0 0 5 )。在二万次对向挤压后 ,正常生理标准组的椎体间距离变化显著 (P <0 0 5 )。结论 Dick钉适合于后部韧带完整的脊柱骨折。Dick钉配合后柱重建术在治疗脊柱三柱骨折中 ,可有效改变Dick系统的受力分布 ,从而起到防止Dick钉弯曲及断裂的作用。

Objective [HT5”SS]By doing biomechanical tests on animal models of spinal fracture to study the importance of reconstruction of the posterior column of the spine for the prevention of Dick screw from breaking.[HT5”H]Methods [HT5”SS]Porcine models of fracture of the spine were treated with internal fixation with three different kinds of Dick screw.One group of normal animals was used as control.All specimens were put on the squeezing machine for the measurement of the change of the height of the vertebral bodies;the data were compared.[HT5”H]Results [HT5”SS]The height of the vertebral bodies in the three spinal column with fractures changed remarkablly( P <0 05)following the first ten thousand times of squeezing.The height of the vertebral bodies in the control group also changed notably after the second ten thousand times of squeezing( P <0.05).[HT5”H]Conclusion [HT5”SS]Dick screw internal fixation is justified for the treatment of spinal fracture with the posterior ligament intact.The repaire of the posterior column of the spine can change the force distribution of Dick internal fixation system effectively and has the function of preventing Dick screw from bending and breaking during the course of spinal fracture treatment. [WT5”HZ]