双侧关节突关节切除致椎间盘退变的影像学观察

Radiological observation of intervertebral disc degeneration caused by bilateral zygopophysial joint resection in rabbit

[目的]探讨新西兰大白兔腰椎关节突关节破坏能否诱发出椎间盘退变的影像学改变。[方法]45只新西兰大白兔，体重2．25～2．95kg，雄性。随机分为骨性手术组和软组织手术组。软组织手术组骨膜下剥离L3至b的椎旁肌肉：骨性手术组完整切除L4、5，双侧下关节突、L5棘突，保留L5、6上关节突。骨性手术组L4、5、L5、6椎间盘为实验组椎间盘，上下相邻的L3、4、L6、7，为自身对照组椎间盘。软组织手术组L4、5、L5、6。椎间盘为实验对照组椎间盘。术后1、2、4及8个月行X线检查。计数不同组别椎间盘退变的异常X线征象发生频数并进行统计分析。[结果]术后1个月，实验组椎间盘开始出现软骨终板钙化。随着时间推移，椎间隙狭窄、椎体边缘骨赘、软骨终板钙化发生频数逐渐增多，与实验对照组、自身对照组比较具有统计学差异。术后8个月，骨性手术组中大部分动物出现以L4、5、或L5、6为中心的角状后凸畸形。[结论]L4、5、L5、6。关节突关节破坏导致椎间失稳，椎间失稳后可以诱发出椎间盘退变的影像学改变。

[ Objective] To study the intervertebral disc degeneration induced by bilateral zygopophysial joint resection in New Zealand rabbits. [Method] Forty-five New Zealand rabbits were randomly divided into 3 groups： group A, L4 and L5 inferior articular processes were en bloc excised, L5 and L6 superior articular processes were retained; its L6,7 and L3,4 as self-control group B; L3 to L7 paravertebral muscles were stripped and took L4,5 , C5,6 as control group C. At one, two, four and eight months postoperatively, anterior-posterior and lateral X-ray film abnormal signs, including intervertebral space wedging, osteo- phyma formation at the edge of vertebral body and cartilage end plate celcification, were examined and counted. [ Result] In the group C, cartilage end plate calcification, seldom intervertebral space narrowing, rare osteophyma formation at the edge of vertebral body and no lumbar spinal kyphosis were found in some rabbits. In the group A, cartilage end plate calcification began to found in the early stage on the L4,5 and Ls,6 , as time went on to the 8^th month postoperatively, almost all rabbits were found intervertebral space narrowing, osteophyma.formation of vertebral space narrowing, osteophyma formation of vertebral body and cartilage end plate calcification. Conform kyphosis of L5,6 were also occurred at some rabbits. There was significant difference between group A and group C, but no difference with group B. [ Conclusion] Radiological changes of L5,6 intervetevbral disc degeneration can be induced by excision of L5 and L6 zygopokhysial joint of rabbit.