摘要
目的：观察不同骨水泥对椎弓根螺钉的加固作用及其对相邻脊髓的影响。方法：犬４０只。腰椎后路切除Ｌ２～３和Ｌ４～５椎板及小关节后，采用椎弓根螺钉技术分别固定各运动节段。根据椎弓根螺钉置入方法分为标准钻孔、过大钻孔无加固、过大钻孔常规骨水泥或可塑性磷灰石骨水泥加固组。每组分别于术后立即和术后８周各取材５只。取材后各固定节段分别在力学测试机上进行整体刚度和螺钉的抗拉出强度测定。光镜下观察相应平面之脊髓的组织学变化。结果：术后立即和８周过大钻孔无加固组的整体刚度和螺钉抗拉出强度均明显低于标准钻孔组和过大钻孔常规骨水泥或磷灰石骨水泥加固组。两种骨水泥加固后的整体刚度和螺钉抗拉出强度与标准钻孔组无显著性差别。组织学检查未发现脊髓形态异常。结论：常规骨水泥和磷灰石骨水泥对松脱之椎弓根螺钉均有显著的加固作用。
Objective: To observe the ability of different bone cements to augment pedicle screw fixation and the effect of the cements on the adjacent spinal cord. Methods: Forty dogs underwent bilateral facetectomy and were stabilized with pedicle screwrod construct over L2～3 and L4～5. Depending on the insertion of the screw, the dogs were divided into four groups: standard drill, overdrilled, overdrilled with augmentation of regular cement (polymethylmethacrate, PMMA) or a remodeble calcium phosphate cement(RCPC). Five dogs of each group were sacrificed immediately and five were sacrificed 8 weeks postoperatively. The motion segment stiffness and the pullout strength of the screw were tested on a MTS. The spinal cord was examined under microscope. Results: The overdrilled screw constructs were found to be significantly weaker than standard and overdrilled screw constructs augmented with PMMA and RCPC in groups sacrificed immediately and 8 weeks postoperatively. There was no significant difference in the motion segment stiffness and pullout strength of the screw among the standard and overdrilled screw augmented with PMMA or RCPC. No significant neurohistologic change was observed. Conclusion: Either PMMA or RCPC significantly improves pedicle screw fixation.
出处
《第二军医大学学报》
CAS
CSCD
北大核心
1997年第6期572-574,共3页
Academic Journal of Second Military Medical University
基金
美国脊柱侧弯研究会资助
