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

急性发作的严重背痛往往是由椎间盘突出引起的。在文献中，通过我们在本项目框架内的先前工作，特别是复杂和动态载荷增加了腰椎椎间盘突出的风险。本DFG项目的目的是研究可能导致腰椎间盘突出的机制。在该项目的过程中，探索了哪些患者活动和先前的损伤会导致腰椎间盘撕裂，以及这些撕裂如何扩散到整个椎间盘。为此，将人供体脊柱加载到具有不同动态加载方案的椎间盘加载模拟器中。这些动态负荷方案反映了患者的活动，这些活动通常与椎间盘突出风险增加有关，例如“弯腰和旋转背部”举起重物。使用这种新的方法，椎间盘突出症被成功地挑起，并在体外更详细地研究了在生理条件下对腰椎羊和人类脊柱节段。除了回答有关腰椎间盘突出症机制的各种基本科学问题外，这还允许在实际载荷条件下评估外科手术和新植入物。在当前项目的过程中，将发现从腰椎转移到颈椎并不像之前假设的那样微不足道，这一点也变得显而易见。颈椎的椎间盘在结构上与腰椎明显不同，是更灵活的脊柱节段，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椎间盘与腰椎相比的解剖学和结构差异。在此基础上，将进一步制定装载协议。该项目的目的是进一步研究颈椎间盘突出症及其起源和发展的机制，以确定危险因素并提出新的治疗方法。然后，这些方案还将用于研究患者日常活动中实际载荷条件下的颈椎植入物。

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.