Moghadas Parshia, Mahomed Aziza, Shepherd Duncan E T, Hukins David W L
School of Mechanical Engineering, University of Birmingham, Birmingham, UK.
School of Mechanical Engineering, University of Birmingham, Birmingham, UK
Proc Inst Mech Eng H. 2015 Mar;229(3):264-8. doi: 10.1177/0954411915576537.
The Charité(®) lumbar intervertebral disc replacement was subjected to wear testing in an electro-mechanical spine simulator. Sinusoidally varying compression (0.6-2 kN, frequency 2 Hz), rotation (±2°, frequency 1 Hz), flexion-extension (6° to -3°, frequency 1 Hz) and lateral bending (±2°, frequency 1 Hz) were applied out of phase to specimens immersed in diluted calf serum at 37 °C. The mass of the ultra-high-molecular weight polyethylene component of the device was measured at intervals of 0.5, 1, 2, 3, 4 and 5 million cycles; its volume was also measured by micro-computed tomography. Total mass and volume losses were 60.3 ± 4.6 mg (mean ± standard deviation) and 64.6 ± 6.0 mm(3). Corresponding wear rates were 12.0 ± 1.4 mg per million cycles and 12.8 ± 1.2 mm(3) per million cycles; the rate of loss of volume corresponds to a mass loss of 11.9 ± 1.1 mg per million cycles, that is, the two sets of measurements of wear agree closely. Wear rates also agree closely with measurements made in another laboratory using the same protocol but using a conventional mechanical spine simulator.
对Charité（®）腰椎间盘置换物在机电脊柱模拟器中进行了磨损测试。对浸于37℃稀释小牛血清中的样本施加正弦变化的压缩（0.6 - 2kN，频率2Hz）、旋转（±2°，频率1Hz）、屈伸（6°至 - 3°，频率1Hz）和侧弯（±2°，频率1Hz），且这些运动不同步。该装置的超高分子量聚乙烯部件的质量在0.5、1、2、3、4和5百万次循环的间隔进行测量；其体积也通过微型计算机断层扫描测量。总质量和体积损失分别为60.3±4.6mg（平均值±标准差）和64.6±6.0mm³。相应的磨损率分别为每百万次循环12.0±1.4mg和每百万次循环12.8±1.2mm³；体积损失率相当于每百万次循环质量损失11.9±1.1mg，即两组磨损测量结果非常接近。磨损率也与另一个实验室使用相同方案但使用传统机械脊柱模拟器所做的测量结果非常接近。
