Loads on a spinal implant measured in vivo during whole-body vibration
Loads on a spinal implant measured in vivo during whole-body vibration
复制标题
DOI：
10.1007/s00586-010-1346-5
复制
发表时间：
2010-07-01
影响因子：
2.8
通讯作者：
Bergmann, Georg
中科院分区：
文献类型：
--
作者：
Rohlmann, Antonius;Hinz, Barbara;Bergmann, Georg
脊柱手术后，患者通常想知道驾驶汽车或使用公共交通工具是否会对他们的脊柱造成危险。为了回答这个问题，一种经临床证实的椎体置换术（VBR）被修改。六个负载传感器和一个遥测单元集成到感应供电的植入物中。改良后的植入物可以测量六个负载分量。5例患者植入遥测装置；其中四人同意将自己暴露在全身振动中。在测量过程中，患者坐在固定在六足架上的驾驶员座椅上。它们暴露在X， Y和Z方向以及多轴XYZ方向的随机单轴振动中，频率在0.3和30 Hz之间。采用三个强度水平（未加权均方根值0.25、0.5和1.0 m/s(2)）。研究了三种姿势：自由地坐着，使用垂直靠背，靠背倾斜25A度。病人们把手放在大腿上。正如预期的那样，VBR上的最大作用力随着强度和轴数的增加而增加。对于最高强度水平和多轴振动，与放松坐着相比，最大力增加了89%。靠在靠背上以及较低的强度水平显著降低了植入物负荷。当病人靠在椅背上时，开车或乘坐公共交通系统会导致植入物的负荷比走路要低，因此可以在手术后不久就被允许使用。
After spinal surgery, patients often want to know whether driving a car or using public transportation can be dangerous for their spine. In order to answer this question, a clinically proven vertebral body replacement (VBR) has been modified. Six load sensors and a telemetry unit were integrated into the inductively powered implant. The modified implant allows the measurement of six load components. Telemeterized devices were implanted in five patients; four of them agreed to exposure themselves to whole-body vibration. During the measurements, the patients sat on a driver seat fixed to a hexapod. They were exposed to random single-axis vibrations in X, Y, and Z directions as well as in multi-axis XYZ directions with frequencies between 0.3 and 30 Hz. Three intensity levels (unweighted root mean square values of 0.25, 0.5 and 1.0 m/s(2)) were applied. Three postures were studied: sitting freely, using a vertical backrest, and a backrest declined by an angle of 25A degrees. The patients held their hands on their thighs. As expected, the maximum force on the VBR increased with increasing intensity and the number of axes. For the highest intensity level and multi-axis vibration, the maximum forces increased by 89% compared to sitting relaxed. Leaning at the backrest as well as lower intensity levels markedly decreased the implant loads. Driving a car or using public transportation systems-when the patient leans towards the backrest-leads to lower implant loads than walking, and can therefore be allowed already shortly after surgery.