Elliott Dawn M, Sarver Joseph J
McKay Orthopaedic Research Laboratory, University of Pennsylvania, Philadelphia 19104-6081, USA.
Spine (Phila Pa 1976). 2004 Apr 1;29(7):713-22. doi: 10.1097/01.brs.0000116982.19331.ea.
Measure the mechanical properties of the mouse and rat disc in compression and torsion.
Validate mouse and rat disc as a biomechanical model of the human disc by comparing the normalized properties in compression and torsion loading.
Rodents have been widely used as models to study disc degeneration; however, mechanical assessments of the rodent disc have been limited. Mouse and rat disc mechanical properties have not been determined.
Mechanically test mouse and rat motion segments from both the lumbar and the caudal levels in axial compression and torsion. Normalize the stiffness using disc geometry and compare with human motion segment stiffness taken from the literature. Compare lumbar and caudal levels with each other within each species, and test for correlation between mechanics and body weight.
The average compression stiffness, normalized by geometry, was 2-4 MPa and compared well with human motion segment stiffness in compression (3-9 MPa). The average torsion stiffness, normalized by disc geometry, was 5-11 MPa and compared well with human motion segment stiffness in torsion (2-9 MPa). Differences between the lumbar and caudal levels were observed. For the caudal tail, no correlation between body weight and any compression property was observed, but for the lumbar spine, some correlations were observed. CONCLUSIONS.: This study provides validation for the mouse and rat disc as a mechanical model of the human disc. Correlations between lumbar spine properties and animal body weight provide support for the use of quadruped animal lumbar spines as mechanical models of the bipedal human spine. The differences between lumbar and tail mechanics need further exploration. These findings are important in light of the extensive use of the rodent in disc studies and the expected future utility of genetically engineered mice.
测量小鼠和大鼠椎间盘在压缩和扭转时的力学性能。
通过比较压缩和扭转加载下的标准化性能，验证小鼠和大鼠椎间盘作为人类椎间盘的生物力学模型。
啮齿动物已被广泛用作研究椎间盘退变的模型；然而，对啮齿动物椎间盘的力学评估有限。小鼠和大鼠椎间盘的力学性能尚未确定。
对来自腰椎和尾椎水平的小鼠和大鼠运动节段进行轴向压缩和扭转的力学测试。使用椎间盘几何形状对刚度进行标准化，并与文献中获取的人类运动节段刚度进行比较。比较每个物种内腰椎和尾椎水平，并测试力学与体重之间的相关性。
经几何形状标准化后的平均压缩刚度为2 - 4兆帕，与人类运动节段的压缩刚度（3 - 9兆帕）比较良好。经椎间盘几何形状标准化后的平均扭转刚度为5 - 11兆帕，与人类运动节段的扭转刚度（2 - 9兆帕）比较良好。观察到腰椎和尾椎水平之间存在差异。对于尾椎，未观察到体重与任何压缩性能之间的相关性，但对于腰椎，观察到了一些相关性。结论：本研究验证了小鼠和大鼠椎间盘作为人类椎间盘力学模型的有效性。腰椎性能与动物体重之间的相关性为将四足动物腰椎用作两足人类脊柱力学模型提供了支持。腰椎和尾部力学之间的差异需要进一步探索。鉴于啮齿动物在椎间盘研究中的广泛应用以及基因工程小鼠预期的未来用途，这些发现具有重要意义。
