腰椎板开窗术后微小骨粒回植模型的建立及意义

Establishment of a rabbit model of lumbar laminectomy and bone grains replantation

目的建立兔腰椎板开窗术后微小骨粒回植模型,为临床提供实验依据。方法将18只雄性新西兰兔,分为两组。对照组在全麻后以L5棘突为中心,充分显露左侧L5椎板,用微型小枪钳慢慢咬去椎板、黄韧带,进行开窗术,暴露约0.8 x 0.3 cm大小骨窗后直接缝合处理。实验组在L5左侧开窗后将开窗咬下的碎骨粒剪碎,然后将碎骨粒镶嵌于医用胶原蛋白海绵,塑成拱桥形,放置于硬膜外开窗处,缝合切口,术后观察椎板开窗位置CT及组织学变化。结果 CT检查示术后8周实验组开窗处微小骨粒形成菲薄的骨板,12周后形成的骨板较厚,骨梁连续,椎管形态及容积无明显变化,未见脊髓受压。对照组开窗处在8、12周局部有少量骨质增生,周围黏连组织侵入椎管,椎管未重建。结论兔椎板开窗处再植自体微小骨粒的骨重建,形成的骨板可遮挡疤痕侵入椎管,减少椎管内黏连。

Objective To establish a rabbit model of lumbar laminectomy and bone grains replantation and provide experimental evidence for the clinical application. Methods Eighteen healthy male New Zealand rabbits were selected and randomly divided into two groups： the control group（ n = 6） and experimental group（ n = 12）. The rabbits of control group were given general anesthesia,and taking the L5 spinous process as the center to perfom left L5 laminectomy,using a micro lancet forceps to slowly bite the lamina and ligamentum flavum for fenestration and exposed to an approximately 0. 8cm x 0. 3 cm sized bone window and then sutured the skin. The rabbits of experimental group were exposed to an approximately 0. 8 x 0. 3 cm sized bone window as well,and bone fragments were cut into small grains. Then the small bone grains were embedded in medical collagen sponge,to form an arch shape,and replanted them to the site of epidural fenestration. CT scan and histological changes were observed at 4,8 and 12 weeks after operation. Results At 8 weeks after operation,CT examination showed that in the experimental group,a thin bone plate was formed by the bone grains. At12 weeks after operation,the bone plate became thicker and was connected with the vertebral bone,and with continuous bone trabeculae. The spinal canal and volume were not obviously changed,and no spinal cord compression was observed.The rabbits of control group showed segment lamina defects,a small scar protruding into the spinal canal,and the vertebral canal was not completely reconstructed. Conclusions The bone grains replantation can effectively promote bone reconstruction in the laminectomized rabbits,and the formed bone plate can prevent epidural scar from intruding into the spinal canal,and can reduce the postlaminectomy adhesion.