目的 研究椎间纤维融合后脊柱节段的稳定性,探讨一种治疗脊柱不稳的新方法.方法 手术剥离纤维环并去除髓核后,刮除软骨终板,在椎间植入环状聚乳酸-聚羟基乙酸(PLGA)可吸收支架,以期椎间纤维组织及血管长入,达到椎间微动融合,模拟椎间盘的生物力学功能.将12只6～8月龄的新西兰白兔随机分为两组,均摘除L4-5椎间盘髓核,A组在椎间植入PLGA可吸收支架;B组单纯髓核摘除.于术前、术后12周行X线检查,运用Image J软件测量椎间盘高度指数(DHI)计算%DHI,分别于术后8、12周处死动物,行组织病理及免疫组织化学染色观察.结果 11只实验动物术后存活至预期时间.12周后,侧位X线片示两组实验动物椎间高度较术前均有下降,两组椎间高度比较差异无统计学意义(P＞0.05),A、B两组实验动物屈伸活动度与术前相比差异均无统计学意义(P＞0.05).动力位相显示两组实验动物手术节段椎体无明显移位及反向成角.术后8周组织学观察:B组椎间盘内纤维组织增生形成瘢痕样组织;A组有大量类软骨细胞增生伴丰富的新生血管长入,未见到支架材料结构.结论 利用椎体骨髓血及其诱导成骨作用可以形成椎间纤维融合;椎间纤维融合能够维持一定的脊柱节段稳定性并保留部分生理活动功能.%Objective To detect the segmental stability of fiber fusion, and to develop a new procedure for treating spine segmental instability. Methods After L4/5 nucleotomy, cartilage endplate was struck off, then a ringlike PLGA scaffold was implated. The composite was tested in 12 New Zea-land white rabbits(6 - 8 months old) which were randomly divided into 2 groups: nucleotomy with PLGA implantation(group A)after drilling holes on the vertebral endplate,nucleotomy alone(group B). X-ray were performed before and 12 weeks after the operation,the DHI were measured using Image J software. Evaluation of disc height, segmental stability, flexion-extension ROM,biomechanics and immunohistochemical analysis were performed and their results were recorded. Results 11 animals were alive after operation. 12 weeks later, disc height decreased in both groups, no insignificant difference between group A and group B(P>0. 05) ,no insignificant difference between ROM of two groups and preoperative(P>0. 05). The Flexion-extension lateral X-ray of two groups hadn t showed Vertebral surge or reverse angle. No PLGA scaffolds structure was found at 8 weeks postoperatively,fibrillar connective tissue formation was evidenced in both groups,but amount of chondrocyte cells and neo-capillaries proliferated in group A. Conclusion Bone marrow blood of vertebra can form relatively effective fiber fusion as well as reconstruct segmental stability and preserve segmental motion.
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