Investigation of the mechanical regulation of lumbar inter-corporeal spinal fusion

椎间盘退变是引起特定腰痛的最常见原因之一。由于多种原因，退变可导致节段不稳定。前路椎体间融合术是目前矫正节段性脊柱不稳最有效的手术治疗方法。在大多数情况下，采用椎笼结合自体松质骨来实现一个或多个椎节的永久骨融合。脊柱融合术最常见的并发症之一是不愈合，通常是由于机械原因（如不稳定、超载、应力屏蔽）和生物原因（如血管化受限）。因此，刚性植入物的插入导致融合区骨形成所需的机械刺激减少。这可能导致早期种植体失败、稳定性丧失或种植体错位和疼痛；伴有相当大的健康风险和再次手术的必要性。椎体间脊柱融合术中骨形成的过程尚不清楚。因此，本研究项目的主要目的是研究腰椎融合术后腰椎融合的机械调节。为此，将建立腰椎运动节段的有限元模型，纳入影响融合过程的机械和生物因素。这些知识将使我们能够确定导致某些患者延迟愈合或骨不连的因素。此外，将针对腰椎优化固定架，与临床可用的植入物相比，这将显著增强骨骼固定并减少完全骨融合所需的时间。这将降低骨不连和翻修手术的风险以及相关的医疗费用。

The degeneration of the intervertebral disc is one of the most common causes of specific lower back pain. Due to multiple reasons, degeneration can lead to segmental instability. Anterior inter-corporeal spinal fusion is currently the most effective surgical treatment to correct segmental instability. In most cases, a spinal cage in combination with autogenous cancellous bone is used to achieve a permanent bony fusion of one or more vertebral segments. One of the most common complications of spinal fusion is nonunion, often due to mechanical (e.g., instabilities, overloading, stress shielding) and biological (e.g., restricted vascularization) reasons. Thereby, the insertion of a rigid implant causes a reduction in the mechanical stimulus required for bone formation in the fusion region. This can result in early implant failure, loss of stability or malposition of the implant and pain; associated with considerable health risks and the necessity for re-operation.The process of bone formation during inter-corporeal spinal fusion is poorly understood. Therefore, the main goal of this research project is to investigate the mechanical regulation of lumbar spinal fusion following spondylodesis. For this purpose, finite element models of lumbar motion segments will be developed, that incorporate the mechanical and biological factors influencing the fusion process. This knowledge will allow us to identify factors contributing to delayed healing or nonunions in some patients. In addition, cages will be optimized for the lumbar spine, which will significantly enhance skeletal fixation and reduce the time required for complete bony fusion compared to clinically available implants. This should reduce the risk of non-unions and revision surgeries as well as the associated health care costs.