Lama Polly, Zehra Uruj, Balkovec Christian, Claireaux Henry A, Flower Luke, Harding Ian J, Dolan Patricia, Adams Michael A
Department of Anatomy, Sikkim Manipal University, Sikkim, India,
Eur Spine J. 2014 Sep;23(9):1869-77. doi: 10.1007/s00586-014-3399-3. Epub 2014 Jun 20.
Disc herniations sometimes contain hyaline cartilage fragments, but their origins and significance are uncertain.
Herniations were removed surgically from 21 patients (aged 35-74 years) whose main symptom was sciatica (10 patients) or back pain (11 patients). Frozen sections, 5 µm thick, were examined histologically, and antibodies were used to label the matrix-degrading enzyme MMP 1, pro-inflammatory mediator TNFα, and cell proliferation marker Ki-67. Proportions of each tissue type were quantified by image analysis. Cartilage and bone components of the endplate were examined in 7-µm frozen sections from 16 cadaveric spines, aged 61-98 years.
Cartilage fragments were found in 10/21 herniations. They averaged 5.0 mm in length, comprised 25 % of the herniation area, and two had some bone attached. Hyaline cartilage was more common in herniations from patients with sciatica (7/10) than with back pain (3/11, P = 0.050), and the area (%) of the herniation occupied by the cartilage was greater in sciatica patients (P < 0.05). Cartilage fragments showed little evidence of swelling, proteoglycan loss or inflammatory cell invasion, although cell clustering was common, and TNFα was sometimes expressed. Each cartilage fragment showed at least one straight edge, as if it had been peeled off the bony endplate, and this mechanism of failure was demonstrated in preliminary mechanical experiments.
Disc herniations often include hyaline cartilage pulled from the vertebral endplates. Cartilage fragments show little swelling or proteoglycan loss, and may be slow to resorb, increasing the risk of persisting sciatica. Loss of cartilage will increase endplate permeability, facilitating endplate inflammation and disc infection.
椎间盘突出有时包含透明软骨碎片，但其起源和意义尚不确定。
对21例主要症状为坐骨神经痛（10例）或背痛（11例）的患者（年龄35 - 74岁）进行手术摘除椎间盘突出物。对5微米厚的冰冻切片进行组织学检查，并用抗体标记基质降解酶MMP 1、促炎介质TNFα和细胞增殖标志物Ki - 67。通过图像分析对每种组织类型的比例进行定量。对16个年龄在61 - 98岁的尸体脊柱的7微米冰冻切片中的终板软骨和骨成分进行检查。
在21个椎间盘突出物中有10个发现了软骨碎片。它们平均长度为5.0毫米，占突出物面积的25%，其中两个附着有一些骨头。透明软骨在坐骨神经痛患者的椎间盘突出物中（7/10）比背痛患者（3/11，P = 0.050）更常见，并且坐骨神经痛患者中软骨所占突出物的面积（%）更大（P < 0.05）。软骨碎片几乎没有肿胀、蛋白聚糖丢失或炎性细胞浸润的迹象，尽管细胞聚集很常见，并且有时会表达TNFα。每个软骨碎片至少有一条直边，就好像是从骨终板上剥离下来的，并且这种破坏机制在初步力学实验中得到了证实。
椎间盘突出常包含从椎体终板撕下的透明软骨。软骨碎片几乎没有肿胀或蛋白聚糖丢失，可能吸收缓慢，增加了坐骨神经痛持续存在的风险。软骨的丢失会增加终板通透性，促进终板炎症和椎间盘感染。
