纳米羟基磷灰石/聚酰胺复合材料预防椎板切除后椎管狭窄、粘连的初步影像研究

目的：探讨影像学关于纳米羟基磷灰石／聚酰胺复合材料（n-HA／pA66）在预防椎板切除后并发症的表现，通过病理对照研究来提供临床指导。方法：建立22只家犬L5椎板切除实验模型，随机分成实验组和对照组。术后行CR和MRI扫描等影像方法与组织学的检测。结果：X线结果术后8周人工椎板与骨接触面开始模糊，至术后24周人工椎板与骨接触界面消失，密度增高，钙化；而对照组始终表现为腰5椎板棘突缺损，无致密影出现。组织学结果术后8周人工椎板内层的纤维组织-材料界面就出现较多成骨细胞团及骨小梁；对照组椎板缺损处是纤维瘢痕逐步形成，最终与硬膜粘连。MRI对脊髓受压及硬膜粘连情况显示较好，实验节段与对照节段相比，椎管面积及矢状径有明显差异（P〈0．05）。显示出重建椎板节段椎管完整性得到恢复，与组织学一致。结论：n-HA／PA66复合材料能够阻止硬膜外粘连，X线及MRI对其检测准确、全面。

An tentative radiological and basical studies of preventing the constriction after the laminectomy by using the nano-hydroxyapatite/polyamide-66 composite material artificial vertebral lamina

Objective: To discuss the radiological evaluation after the experiment implanted artificial vertebral lamina made from n-HA/PA66 into the defect of vertebral lamina,in order to evaluate its value in preventing the complication of postlaminectomy.Methods:22 male dogs aged one year were classified randomly into three groups: the experimental group(13 dogs)and the control group(9 dogs).The specimens were examined by the methods of plain roentgenography,MRI and histology.Results:The X-ray: in the experimental group,it was becoming cloudy around the operative area in the 8th week;till 24th week,the density of the operative area was the same with the density of bone.The histology: in the experimental group,from the 8th week,there were many cartilage cells and lamellar bone observed.While in the control group,it was just fibrous layer forming.MRI:the reconstructed segment after the laminoplasty was detected clearly by MRI,which coincided with the histology.Compared with the control segment,the numbers of the area of vertebral canal and the sagital axis were significantly different(P<0.05).Conclusion: The experimental results show that n-HA/PA66 composite material not only has the attribute of good biocompatibility,but also can effectively prevent the scar formation and adhesion.,which can be detected by the X-ray and MRI exactly.