Galbusera Fabio, Wilke Hans-Joachim, Brayda-Bruno Marco, Costa Francesco, Fornari Maurizio
Institute of Orthopaedic Research and Biomechanics, Center of Musculoskeletal Research Ulm (ZMFU), University of Ulm, Ulm, Germany.
Clin Biomech (Bristol). 2013 Apr;28(4):370-7. doi: 10.1016/j.clinbiomech.2013.02.006. Epub 2013 Mar 11.
Pathological deformities involving the sagittal alignment of the spine may lead to loss of spine stability and imbalance. The effect of different patterns of sagittal balance on the loads acting in the spine was only marginally investigated, although it would be of critical importance in the clinical management of spinal disorders.
Optimization-based finite element models of the human spine in the standing position able to predict the loads acting in the lumbar spine and the activation of the spinal muscles were developed and used to explore a wide range of sagittal balance conditions, covering both inter-subject variability and pathological imbalance. 1000 two-dimensional randomized spine models with simplified geometry were generated by varying anatomical parameters such as lumbar lordosis, sacral slope, and C7 plumb line. Muscular loads were calculated by means of an optimization procedure aimed to minimize total muscular stress.
The simulation of a physiological spine in the standing position predicted average disk stresses ranging from 0.38 to 0.5MPa, in good agreement with in vivo measurements. The C7 plumb line and the parameters describing the lumbar spine were found to be the strongest determinants of the lumbar loads and muscle activity. Marginal relevance was found concerning the thoracic and cervical parameters.
The present modeling approach was found to be able to capture correlations between sagittal parameters and the loads acting in the lumbar spine. The method represents a good platform for future improvements aimed at patient-specific modeling to support pre-operative surgical planning.
涉及脊柱矢状面排列的病理性畸形可能导致脊柱稳定性丧失和失衡。尽管矢状面平衡的不同模式对脊柱负荷的影响在脊柱疾病的临床管理中至关重要，但对此的研究仅处于边缘状态。
建立了基于优化的人体脊柱站立位有限元模型，该模型能够预测腰椎的负荷以及脊柱肌肉的激活情况，并用于探索广泛的矢状面平衡条件，包括个体间差异和病理性失衡。通过改变诸如腰椎前凸、骶骨倾斜度和C7铅垂线等解剖学参数，生成了1000个具有简化几何形状的二维随机脊柱模型。通过旨在最小化总肌肉应力的优化程序计算肌肉负荷。
站立位生理脊柱的模拟预测平均椎间盘应力范围为0.38至0.5MPa，与体内测量结果高度吻合。发现C7铅垂线和描述腰椎的参数是腰椎负荷和肌肉活动的最强决定因素。关于胸椎和颈椎参数的相关性较小。
发现当前的建模方法能够捕捉矢状面参数与腰椎负荷之间的相关性。该方法是未来旨在进行患者特异性建模以支持术前手术规划的改进的良好平台。
