兔腰椎间盘髓核穿刺抽吸后的影像及组织病理学变化

背景：髓核摘除后椎间盘会随时间出现什么样的影像学及组织病理学变化，目前尚不明确。目的：观察兔腰椎间盘髓核穿刺抽吸术后影像学及组织病理学的变化。方法：32只日本大耳白兔，用21号针头行L3“椎间盘后外侧穿刺抽吸出部分髓核组织，L2/3椎间盘作为正常对照椎间盘，于抽吸后2，4，8，12周时按照分组取8只兔子行腰椎侧位X射线检查，测量L3/4、L2／3椎间隙高度并计算椎间盘高度指数，行正中矢状位MRI检查及椎间盘组织病理学检查。结果与结论：髓核抽吸后2，4，8，12周椎间盘高度呈逐渐降低趋势，但8-12周变化减小，与正常对照组椎间盘相比，各时间点椎间盘高度指数显著降低（尸〈0．05）。抽吸后2，4，8，12周的髓核信号强度随时间逐渐降低，8周时已达改良Thompson分级标准的4级。抽吸后凝胶状髓核组织随时间逐渐出现裂隙，形态逐渐紊乱，12周时呈现明显的纤维化表现，髓核4周时出现较多的类软骨细胞，呈现活跃状态，髓核细胞明显减少，抽吸后8．12周髓核内纤维样细胞增多，类软骨细胞数量减少，纤维环随时间逐渐出现扭曲，排列紊乱，突起，出现分层、纤维断裂现象。说明后外侧纤维环穿刺髓核抽吸后，兔腰椎间盘X射线高度、MRIT2加权信号强度随时间逐渐降低、减弱，椎间盘组织逐渐出现退变病理改变，但8—12周其变化趋于缓和。

Alterations in imaging and histopathology after aspiration of nucleus pulposus of rabbit lumbar intervertebral disc

BACKGROUND： It remains unclear what kind of changes in imaging and histopathology would appear in intervertebral disc after removal of nucleus pulposus over time. OBJECTIVE： To observe the alteration in imaging and histopathology of rabbit lumbar intervertebral disc after nucleus pulposus aspiration. METHODS： A total of 32 Japanese rabbits were subjected to nucleus pulposus aspiration in posterior lateral L3J4 intervertebral disc with a 21-gauge hypodermic needle. L2/3 intervertebral disc sewed as a normal control. At 2, 4 8 and 12 weeks after aspiration, eight rabbits according to grouping received radiograph in the lateral position of lumbar vertebra. The height of L3/4 and L2/3 intervertebral space was measured and intervertebral disc height index was calculated. Rabbits received median sagittal MRI examination and histopathological examination of intervertebral disc.RESULTS AND CONCLUSION： The intervertebral disc height degraded slowly at 2, 4, 8, and 12 weeks afteraspiration. However, the difference between 8 and 12 weeks was reduced. Compared with normal control, intervertebra disc height index significantly reduced at various time points （P 〈 0.05）. The nucleus pulposus signal intensity was gradually reduced at 2, 4, 8, and 12 weeks after aspiration, and reached grade 4 of modified Thompson grading criteria at 8 weeks. After aspiration, gelatinous nucleus pulposus of disc slowly exhibited fissures with time, morphous was slowly disordered and showed significant fibrosis performance at 12 weeks. In nucleus pulposus region, more cartilage-like cells were found at 4 weeks after operation. The cells were active. Nucleus pulposus cells decreased significantly. At 8 and 12 weeks after operation, fibroblasts increased in nucleus pulposus region, and the number of cartilage-like cells reduced. The annulus fibrosus gradually became distorted, disordered, with processes and layers, and fiber breakage appeared. These results indicated that after puncturing lateral annulus fibrosus and aspirating the nucleus pulposus, radiograph height of the intervertebral disc and MRI T2-weighted signal intensity gradually reduced. Pathological changes were observed. However, the degeneration alleviated between 8-12 weeks.