特发性脊柱侧凸患者脊柱畸形段凸侧及凹侧关节突松质骨三维微结构比较

目的比较青少年特发性脊柱侧凸(AIS)患者脊柱畸形顶椎区和端椎区两侧关节突松质骨的三维微结构。方法AIS患者9例,均为女性,年龄12～17岁,平均14.9岁;Cobb角48°～84°,平均56°。患者均接受后路矫形融合内固定手术,术前与患者家长签署同意书,在去皮质手术时取下顶椎区和上下端椎区两侧关节突。标本取材后用中性福尔马林固定,然后用解像度为20μm的微焦点CT扫描,三维图像重组进行骨形态计量学测量对比。结果顶椎区凸侧与凹侧相比有显著差异,分别为:骨量容积比BV/TV为0.268/0.354(P<0.05),骨小梁厚度TbTh为0.20/0.24(P<0.05),骨小梁分离度TbSP为0.66/0.56(P<0.05),骨小梁面积体积比BS/BV为12.7/10.4,P<0.05)。端椎区左右两侧关节突松质骨骨小梁无明显差异,上胸椎和胸腰椎关节突骨小梁微结构比较未见差异。结论由于脊柱侧凸凹侧承受不同应力,凹侧关节突出现更多的骨小梁,骨小梁间的连接更紧密,而且骨小梁更粗,从而可使脊椎楔形变的速度变缓,提示脊柱的骨骼本身并不是AIS脊柱侧凸畸形进展的促进因素。

Trabecular bone micro-architecture in adolescent idiopathic scoliosis compared between concave and convex site of the facet joints

OBJECTIVE: To evaluate the trabecular bone micro-structure from different sites of spine in adolescent idiopathic scoliosis patients. The target site consisted of the bilateral facet joints from apical vertebrae and from end vertebrae. METHODS: Nine AIS patients with mean age 14.9 years (range 12-17 years) and mean Cobb angle 56 degrees (ranged 48 degrees-84 degrees) were recruited into this study. Corrective surgery was indicated to these patients, and facet joint biopsies were collected during decortications for spinal fusion. Biopsy consents were obtained from patients. Bone specimens were fixed with routine histology procedures and scanned by micro computer tomography (muCT40, Scanco Medical, Switzerland). Ten pairs of facet joint were harvested from apical vertebrae and 12 pairs from end vertebrae. Three-dimensional reconstructed images with the resolution of 20 microm were achieved for histomorphometric analysis. RESULTS: The values of BV/TV (0.268 vs. 0.354, P < 0.05), TbTh (0.20 vs. 0.24, P < 0.05), TbSP (0.66 vs. 0.56, P < 0.05) and BS/BV (12.7 vs. 10.4, P < 0.05) between convex and concave side at the apex area were significantly different. No difference was found in any structural parameters between left and right side at end area, and upper thoracic (T5, 6) and thoracolumbar (T12, L1). CONCLUSION: Due to asymmetric compression and tension shared between convex and concave side, more bone and thicker and more profound trabecular bones are observed in the concave side than in the convex side, which seems to resist the progression of spinal curvature. This finding suggests that the provocative factors which cause the progression of the curve in certain patients may not lie in the bone component of spine.