Biomechanical analysis of surgical scoliosis treatments

青少年特发性脊柱侧凸（AIS）的手术治疗非常复杂，现代器械技术提供了多种可能性。有许多指南，可帮助外科医生选择适当的手术入路。然而，在最佳战略上仍然没有明确的共识。因此，手术方法特别取决于个体外科医生和脊柱侧凸的类型。 本研究的目的是系统地记录和生物力学分析AIS患者的不同手术策略。该研究分为三个工作包：WP-1：将进行调查，以记录手术策略的差异。来自德国、欧洲和世界各地的经验丰富的脊柱侧凸外科医生将被要求为AIS患者制定手术计划。将通过问卷调查记录手术计划。在对8个中心进行的初步多中心调查中，对问卷的适用性进行了测试，这也使我们能够明确该项目的优先事项。WP-2：通过体外试验，将量化手术测量差异的生物力学影响，包括不同切除步骤对脊柱刚度及其矫正潜力的影响。随后，将对选定的短节段和多节段前路和后路内固定技术进行比较。体外测试将使用我们的脊柱测试仪进行，该测试仪允许对多节段脊柱与所连接的胸腔进行广泛的生物力学分析。WP-3：将生成来自调查的个体患者病例的数值模型，以调查多种手术治疗中的差异。将使用手术入路的体外数据校准建模。为了验证手术治疗的模拟，将数值结果与术后图像进行比较。通过对包括胸部在内的完整脊柱进行建模，同时考虑来自外科医生、患者和体外实验的广泛数据，我们期望更好地了解经验性手术方法的影响。该模型将有助于预测手术结果，并可能改善手术治疗。一个重要的长期目标是研究退行性脊柱侧凸的治疗。与AIS相比，这种脊柱侧凸类型包括退行性过程，因此被认为是多因素的。我们的研究结果将为将来治疗退行性脊柱侧凸提供基础知识。

Surgical treatment of adolescent idiopathic scoliosis (AIS) is very complex and modern instrumentation techniques offer multiple possibilities. There are numerous guidelines, which aid the surgeon in choosing the proper surgical approach. However, there still exists no clear consensus on the optimal strategy. So, the surgical approach depends particularly on the individual surgeon and the type of scoliosis. The goal of this study is to systematically document and biomechanically analyse the different surgical strategies for AIS-patients. The study is split up into three work-packages: WP-1: A survey will be conducted to document the discrepancies in the surgical strategies. Experienced scoliosis surgeons from Germany, Europe and all over the world will be asked to plan surgeries on patients with AIS. The surgical planning will be documented by a questionnaire. The suitability of the questionnaire was tested within a preliminary multi-centre-survey with 8 centres, which has also allowed us to sharpen the priorities of this project. WP-2: With in-vitro tests the biomechanical influence of the discrepancies of the surgical survey will be quantified, including the influence of different resection steps on the stiffness on the spine and their correction potential. Subsequently, selected short and multi-level anterior and posterior instrumentation techniques will be compared. The in-vitro tests will be performed with our spine-tester, which allows extensive biomechanical analyses of multi-level spines with the attached ribcage. WP-3: Numerical models of the individual patient cases from the survey will be generated to investigate the discrepancies in the manifold surgical treatments. The modelling will be calibrated using the in vitro data of the surgical approaches. To validate the simulation of the surgical treatments, the numerical results will be compared with post-operative images. By modelling the complete spine including the chest while considering a wide scope of data from surgeons, patients, and in-vitro experiments, we expect to gain a better understanding of the impact of empirical surgical approaches. The model will help make predictions of surgical outcomes and might improve the surgical treatment. An important long-term objective is the investigation of the degenerative scoliosis treatment. Compared to AIS, this scoliosis type includes degenerative processes and is, therefore, considered strongly multi-factorial. The results of our proposed study will provide fundamental knowledge for tackling also degenerative scoliosis in future investigations.