Spine：胸椎背胸侧剪切加载对旋转稳定性的影响
由于人是直立行走的，所以特发性脊柱侧凸是人类特有的一种疾病状态。人类脊柱的特定部位，尤其是背侧倾斜的下胸椎和上腰椎，易于受到指向背侧的剪切载荷。有假说认为这些背侧剪切载荷降低了脊柱的旋转稳定性，进而增加了形成特发性脊柱侧凸的风险。
目前有荷兰科学家对此应用猪和人尸体的各14具胸椎功能单元标本进行了生物力学测试。对标本在背侧方向和腹侧方向，在脊柱功能单元的上椎体正中矢状面中心加载剪切载荷，试验采用自动化光电子三维运动测量系统测量椎体旋转。试验结果显示，偏心施加剪切载荷会在人与猪的脊柱阶段诱发椎体旋转。在胸正中和下胸位置，背侧剪切载荷比胸侧剪切载荷会产生更明显的椎体旋转。研究证实，对于人和四肢动物，在背侧剪切载荷下比在胸侧剪切载荷下胸椎的旋转稳定性更小。
相关论文发表在《脊柱》（Spine）上。（科学新闻杂志 牛文鑫/编译）
生物谷推荐原始出处：
（Spine），32(23):2545-2550，Kouwenhoven Jan-Willem ，Castelein Rene
Biomechanics
Kouwenhoven, Jan-Willem M. MD *; Smit, Theo H. PhD +; van der Veen, Albert J. MSc +; Kingma, Idsart PhD ++; van Dieen, Jaap H. PhD ++; Castelein, Rene M. MD, PhD *
Abstract:
Study Design. A biomechanical in vitro study on porcine and human spinal segments.
Objective. To investigate axial rotational stability of the thoracic spine under dorsal and ventral shear loads.
Summary of Background Data. Idiopathic scoliosis is a condition restricted exclusively to humans. An important difference between humans and other vertebrates is the fact that humans ambulate in a fully erect position. It has been demonstrated that certain parts of the human spine, more specifically the dorsally inclined lower thoracic and high lumbar parts, are subject to dorsally directed shear loads. It has been hypothesized that these dorsal shear loads reduce the rotational stability of the spine, thereby increasing the risk to initiate idiopathic scoliosis.
Methods. Fourteen porcine and 14 human thoracic functional spinal units (FSUs) with intact costotransverse and costovertebral articulations were used for biomechanical testing. In both dorsal and ventral directions, shear loads were applied to the upper vertebra of the FSU in the midsagittal plane (centrally), and at 1 cm to the right and to the left (eccentrically), resulting in a rotary moment. Vertebral rotation was measured at 3 incremental loads by an automated optoelectronic 3-dimensional (3D) movement registration system.
Results. The results of this study showed that eccentrically applied shear loads induce vertebral rotation in human as well as in porcine spinal segments. At the mid-thoracic and lower thoracic levels, significantly more vertebral rotation occurred under dorsal shear loads than under ventral shear loads.
Conclusion. These data show that, in humans and in quadrupeds, the thoracic spine is less rotationally stable under dorsal shear loads than under ventral shear loads.
- 众说风云 (已有0条评论)
