椎板再生的实验研究

目的:探讨大鼠椎板切除后的再生机制和后果.方法:以SD大鼠为模型行L5全椎板切除,与对照组一同进行运动和感觉功能检查、影像学及病理学检查,计算机分析结果数据.结果:病理学检查见椎板缺损处首先形成纤维组织,继而椎板边缘松质骨以软骨内成骨的方式向对侧再生形成椎板,椎板皮质骨则以膜内成骨的方式再生,此外纤维组织中出现软骨岛并骨化成椎板.术后16周L5椎管截面积测量结果显示,椎板再生引起实验组椎管狭窄15.6%(P＜0.05),同时实验组出现了明显间歇性跛行(P＜0.05).体感诱发电位(SEP)结果还显示实验组出现了下肢感觉障碍--潜伏期延长(P＜0.05),波幅下降(P＜0.05).结论:椎板再生包括纤维组织软骨内成骨和椎板切缘的骨再生,再生造成椎管狭窄.

Bone regeneration after experimental laminectomy

Objective:To explore the mechanism and aftereffects of bone regeneration after laminectomy in rats.Methods: The SD rats receiving L5 laminectomy as the experimental group and the rats of the control group were evaluated by examinations of sensory and motorial functions as well as radiological and pathological examinations. The results were analyzed by computer. Results:The pathological examination showed that fibrous tissue appeared at the defect after laminectomy firstly, then the cancellous bone regenerated in the form of endochondral ossification to form verterbral lamina, while the cortical bone regenerated in form of intramembranous ossification from the resection margins, besides, chondral bone islands appeared in the fibrous tissue and ossified to form laminae. Sixteen weeks after the operation the cross section area of L5 spinal canal was diminished by 15.6%(P<0.05) resulting from regeneration, meanwhile, obvious intermittent claudication occurred in the experimental group(P<0.05).Somatosensory evoked potential(SEP) latent periods were increased and amplitudes were decreased obviously in the experimental group(both P<0.05), showing damage to the sensory function of the lower limbs. Conclusion:The bone regeneration resulting in stenosis of spinal canal after laminectomy consists of both bone regeneration from the defect margins and the chondral islands ossification in the fibrous tissue.