Analyzing the Influence of Disc Height on Thoracic Spine Mechanics: A Finite Element Approach

This study investigates the influence of intervertebral disc (IVD) height on thoracic spine biomechanics using finite element analysis (FEA) at the T11-T12 segment. A three-dimensional model, derived from CT imaging, was used to compare normal and doubled IVD thickness. In the normal model, stress was uniformly distributed with a maximum von Mises stress of 0.6 MPa in the IVD and 30 MPa overall, ensuring structural integrity. However, the thicker IVD model exhibited heightened stress levels, with von Mises stresses increasing to 4.5 MPa in the IVD and 55.52 MPa in the whole model, a 7.5- and two-fold rise, respectively. Displacement in the thicker IVD model also increased significantly, particularly in the sagittal and frontal planes, indicating reduced spinal stability. These findings demonstrate that excessive IVD thickness disrupts load distribution, increases stress concentration, and impairs stability, exacerbating the risk of herniation and degeneration. The results align with prior studies and highlight the importance of maintaining optimal IVD height for spinal health. This research contributes valuable insights for clinical applications, such as artificial disc design, emphasizing the critical balance between mobility and stability.