脊髓损伤早期及制动大鼠股骨干骺端的显微CT观察

背景：脊髓损伤后可引起损伤平面以下骨量大量丢失,导致骨质疏松。目的：观察比较脊髓损伤及失用性制动模型大鼠股骨远端骨密度及骨微观结构的改变。方法：将SD大鼠随机分为3组：对照组,切除T10椎板,不损伤硬膜及脊髓;脊髓损伤组,切除T10椎板后行Allen's法造成脊髓损伤;制动组,以大鼠双侧腿－尾缝合造成双下肢制动。10 d后取一侧尺、桡骨及股骨行骨密度检测,另一侧股骨行显微CT扫描。结果与结论：脊髓损伤组与制动组大鼠股骨远端骨密度、骨矿物质含量、骨体积分数表、骨小梁厚度、骨皮质面积及厚度、骨小梁数量均低于对照组(P < 0.05 ),骨小梁结构模型指数、骨表面积体积比、骨小梁分离度均高于对照组;脊髓损伤组上述指标较制动组变化程度更显著(P < 0.05)。3组尺、桡骨密度差异无显著性意义。说明脊髓损伤及制动均可导致骨量丢失,在脊髓损伤早期损伤平面以下部位骨微观结构呈现骨质疏松明显改变,且程度比失用性因素严重。

Micro CT observation on femoral metaphysis after spinal cord injury and immobilization in rats

BACKGROUND:Osteoporosis results from spine cord injury (SCI), due to a great deal of bone loss.OBJECTIVE:To make an observation and comparison on bone density and bone microstructure at the distal femora changes after both SCI in early stage and osteoporosis due to immobilization. METHODS:The SD rats were randomly divided into three groups. In the control group, T10 vertebrae plate resection was performed to rats without injuring dura mate of spinal cord and spinal cord. T10 vertebrae plate resection was also performed to rats in the SCI group with spinal cord injury by Allen’s method. Rats in the immobilization group were immobilized by limb-tail fixation at bilateral hindlimbs. The femoral metaphysis, ulna and radius were chosen for detection of bone density individuals and Micro CT scanning was performed to the other femoral metaphysis.  RESULTS AND CONCLUSION:Compared with the control group, bone density, bone mineral content, bone volume/ total volume (BV/TV) , trabecular thickness (Tb.Th), cortical bone area (Ct.Ar), cortical thickness (Ct.Th), trabecular number (Tb.N) in the distal femur of rats in the SCI group and immobilization group deceased dramatically respectively (P < 0.05). Structure model index (SMI), bone surface/ total volume (BS/TV), trabecular separation/spacing (Tb.Sp) in the distal femur of the SCI group was higher than that of the control group (P < 0.05 ). No bone density difference of significance was found in the elbow-bone and radius between the three groups. Above all, both SCI and immobilization can result in osteoporosis. SCI have resulted in significantly changes in the bone microstructure in early stage and compared with the immobilization group, the degree of changes was more seriously.