Investigation of failure and failure propagation in the intervertebral disc caused by mechanical overloads

急性发作的严重背痛通常是由突出的椎间盘引起的。在文献中和我们之前在该项目框架内的工作中，研究表明，特别是复杂和动态的负荷增加了腰椎椎间盘突出的风险。该DFG项目的目的是研究可能导致腰椎间盘突出症的机制。在该项目的过程中，研究了哪些患者的活动和先前的损伤会导致腰间盘撕裂，以及这些撕裂可能如何扩散到整个腰椎间盘。为此，在不同的动态加载方案下，在椎间盘加载模拟器中加载人类供体脊柱。这些动态负荷方案反映了患者经常与增加的椎间盘突出风险相关的活动，例如“弓着背和旋转的背部”抬起沉重的负荷。利用这种新的方法，在生理条件下，成功地在绵羊腰椎和人脊柱节段上成功地诱发了腰椎间盘突出症，并对其进行了更详细的研究。除了回答各种有关腰椎间盘突出症发病机制的基本科学问题外，它还允许在现实负荷条件下评估外科手术程序和新的植入物。在目前的项目过程中，也变得明显的是，将研究结果从腰椎转移到颈椎并不像假设的那样微不足道。颈椎的椎间盘在结构上与腰椎的有很大的不同，到目前为止，它的脊柱节段更灵活，因此可以执行更极端和复杂的运动。因此，在进一步的研究中，将更详细地研究颈椎运动节段和间盘与腰椎相比在解剖和结构上的差异。在此基础上，进一步完善加载协议。项目继续的目的是用这些加载方案进一步研究颈椎间盘突出症及其发生和发展的机制，以确定危险因素并提出新的治疗方法。然后，这些方案还将被用于在患者日常活动期间在现实负荷条件下调查颈椎植入物。

Acute onset of severe back pain is often caused by herniated intervertebral discs. In the liter-ature and through our own previous work within the framework of this project, it was shown that in particular, complex and dynamic loads increase the risk of intervertebral disc herni-ations in the lumbar spine. The aim of this DFG project was to investigate the mechanisms that might lead to a herniation in the lumbar intervertebral disc. In the course of the project, it was explored which patient activities and previous damage can cause tears in the lumbar intervertebral disc and how these might spread throughout the disc. For this purpose, human donor spines were loaded in an intervertebral disc loading simulator with different dynamic loading protocols. These dy-namic loading protocols reflect patient activities that are often associated with an increased risk of disc herniation, such as lifting heavy loads "with a hunched and rotated back". Using this new method, disc herniations were successfully provoked and studied more in detail in vitro on lumbar sheep and human spinal segments under physiological conditions. In addition to answering a variety of basic scientific questions about the mechanisms of lumbar disc her-niation, this allows to evaluate surgical procedures and new implants under realistic loading conditions. In the course of the current project, it also became apparent that transferring the findings from the lumbar spine to the cervical spine is not as trivial as had been assumed. The disc of the cervical spine differs structurally significantly from the lumbar one and is by far more flexible spinal segment and can therefore perform more extreme and complex movements. In further studies therefore, anatomical and structural differences of cervical motion segments and intervertebral discs in comparison to the lumbar spine will be investigated more in detail. On this basis, the loading protocol will be further developed. The aim of the project continua-tion is to further investigate cervical disc herniations and the mechanism of their origin and development with these loading protocols in order to define risk factors and to propose new therapy approaches. These protocols will then also be used to investigate implants for the cervical spine under realistic load conditions during everyday patient activities.