腰椎间盘MRI高信号区的组织病理学特点和临床意义

目的研究椎间盘源性下腰痛患者腰椎间盘纤维环后方MRI高信号区的组织病理学特征及其临床意义。方法对52例经保守治疗无效、CT片显示无腰椎间盘突出的下腰痛患者行腰椎MR检查及腰椎间盘造影术。男39例,女13例;平均年龄38.8岁。选择纤维环后方出现高信号区的部分病例行腰椎后路椎间盘切除、椎体间融合、椎弓根螺钉内固定术,术中收集包括高信号区部位的椎间盘。对标本行矢状面连续组织学切片,光镜下观察高信号区椎间盘组织的组织病理学结构,并分析其临床意义。结果在行腰椎间盘造影的52例142个椎间盘中,17例17个椎间盘显示高信号区,且在椎间盘造影过程中全部呈现2或3级的纤维环破裂和疼痛复制反应。敏感性和特异性均为100%。高信号区与纤维环破裂程度分级呈正相关,说明纤维环破裂程度分级越高,越易出现高信号区(R=0.462,P<0.01)。共收集11例患者11个椎间盘,组织学研究发现对应高信号区的椎间盘组织表现为沿纤维环裂隙形成的不同程度的血管化肉芽组织,有成熟的瘢痕化胶原组织。结论症状性下腰痛患者的腰椎MRI上有椎间盘高信号区,可以作为椎间盘源性下腰痛诊断的重要征象。

Pathologic characteristics and clinical significance of high intensity zone of lumbar intervertebral disc in the patient with discogenic low back pain

Objective To study the pathologic characteristics and clinical significance of high intensity zone (HIZ) of lumbar intervertebral disc in the patients with discogenic low back pain. Methods 52 patients with low back pain without disc herniation underwent MRI and following discography of lumbar vertebrae. All patients previously were treated conservatively without relief of their symptoms for more than 6 months. Specimens of lumbar intervertebral discs containing HIZ in the posterior annulus from 11 patients with discogenic low back pain during posterior lumbar interbody fusion (PLIF) were collected to investigate the morphologic patterns and clinical significance. Results In all of 142 discs in 52 patients at discography, 17 discs in 17 patients presented HIZ, all showed painful reproduction and abnormal morphology with annular tears extending either well into or through the outer third of the annulus fibrosus. The histologic study of the consecutive sagittal slices in the HIZ lesions revealed that the normal lamellar structure was replaced by disorganized, vascularized granulation tissue that consisted of small round cells, fibroblasts, and newly formed blood vessels around the tears extending from the nucleus pulposus to the outer region of the annulus fibrosus. Blood vessel proliferation and inflammatory cell infiltration were seen extending along the margins of the tears into the middle and inner annulus, and sometimes the tears were bridged with granulation tissue. Ingrowth of vascularized tissue was sometimes observed to end abruptly at the junction between the inner third of the annulus and the nucleus pulposus. There was also matured scarring collagenous tissue. Conclusion The HIZ in the lumbar disc in the patients with symptomatic low back pain can be considered as a reliable marker of painful outer annular disruption.