Schmidt T A, An H S, Lim T H, Nowicki B H, Haughton V M
Department of Radiology, Medical College of Wisconsin, Milwaukee, USA.
Spine (Phila Pa 1976). 1998 Oct 15;23(20):2167-73. doi: 10.1097/00007632-199810150-00005.
Biomechanical and anatomic study of human cadaveric spinal motion segments.
To measure the stiffness of spinal motion segments by disc type and by load type (flexion, extension, axial rotation, or lateral bending). To compare stiffness in motion segments with and without a high-intensity zone or radial tear in the anulus fibrosus.
The high-intensity zone, that is a linear zone of high-intensity on T2-weighted magnetic resonance images corresponding to a radial tear in the anulus fibrosus, is a marker for a painful disc at discography. The high-intensity zone is hypothetically associated with diminished stiffness of the motion segment.
Human cadaveric lumbar spinal motion segments with normal disc morphology or a high-intensity zone of the anulus fibrosus were selected on the basis of magnetic resonance imaging. The motion segments were subjected to incremental flexion, extension, rotation, and lateral bending torques. Rotation was measured with a kinematic system. Torque-rotation curves and stiffness were calculated for each motion segment and for each torque. The motion segments were sectioned on a cryomicrotome to verify the disc morphology as normal or as that of a radial tear.
In four motion segments with normal discs, stiffness was greater in axial rotation (8.4 Nm/degree) than in lateral bending (2.3 Nm/degree), flexion (1.8 Nm/degree), or extension (2.6 Nm/degree). In 16 motion segments with a high-intensity zone, stiffness was 2.4 Nm/degree in axial rotation, and less severely reduced in lateral bending, flexion, and extension. Stiffness in motion segments with a high-intensity zone was significantly less with smaller than with larger axial rotation loads.
The presence of a high-intensity zone in the intervertebral disc is associated with reduced stiffness of motion segments. The reduction is greater in axial rotation than in other torques. The reduction is more in smaller than in larger axial torques.
人体尸体脊柱运动节段的生物力学与解剖学研究。
按椎间盘类型和载荷类型（前屈、后伸、轴向旋转或侧屈）测量脊柱运动节段的刚度。比较纤维环有无高强度区或放射状撕裂的运动节段的刚度。
高强度区是T2加权磁共振图像上对应纤维环放射状撕裂的高强度线性区域，是椎间盘造影时疼痛椎间盘的一个标志。据推测，高强度区与运动节段刚度降低有关。
根据磁共振成像选择具有正常椎间盘形态或纤维环高强度区的人体尸体腰椎脊柱运动节段。对运动节段施加递增的前屈、后伸、旋转和侧屈扭矩。用运动学系统测量旋转情况。计算每个运动节段和每个扭矩的扭矩 - 旋转曲线及刚度。在冷冻切片机上对运动节段进行切片，以验证椎间盘形态为正常或放射状撕裂。
在4个椎间盘正常的运动节段中，轴向旋转刚度（8.4 Nm/度）大于侧屈（2.3 Nm/度）、前屈（1.8 Nm/度）或后伸（2.6 Nm/度）。在16个有高强度区的运动节段中，轴向旋转刚度为2.4 Nm/度，侧屈、前屈和后伸刚度降低程度较小。轴向旋转载荷较小时，有高强度区的运动节段刚度明显低于载荷较大时。
椎间盘高强度区的存在与运动节段刚度降低有关。轴向旋转时刚度降低比其他扭矩时更明显。轴向扭矩较小时刚度降低比扭矩较大时更明显。
