Construction and validation of U-type finite element model of osteoporotic vertebral compression fracture

Pengfei Li^1,2,3Jihao Mu¹朝 王¹Xiaochong Zhang³Yingze Zhang^4*Dengxiang Liu^3*Ao Li¹

• ¹Harrison International Peace Hospital, Hengshui, China
• ²Hebei Medical University, Shijiazhuang, Hebei Province, China
• ³Xingtai City People's Hospital, Xingtai, Hubei Province, China
• ⁴Third Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, China

Background: Osteoporotic vertebral compression fracture (OVCF) is recognized as a common complication of osteoporosis. The biomechanical alterations in the affected and adjacent vertebrae have a significant influence on patient symptoms, treatment strategies, and clinical outcomes. Nevertheless, establishing an accurate model of OVCF remains a highly challenging task. In this study, a novel finite element model of OVCF is developed and validated, and a comprehensive biomechanical analysis is conducted.Methods: Computed tomography data of the thoracolumbar spine (T12-L2) are collected from an OVCF patient and a healthy volunteer to establish the OVCF and normal models, respectively. Based on the normal model, U-type, V-type, and double-V-type finite element models are constructed. Intervertebral discs and articular cartilage are generated through appropriate combinations and assemblies, followed by the development of three-dimensional finite element biomechanical models. The magnitude and distribution of stress and displacement in these three models are evaluated and compared with those of the OVCF model under various directions of motion.In the force distribution contour diagrams, the U-type model most closely resembles the OVCF model at the T12 vertebra, particularly in the directions of forward flexion, backward extension, left lateral bending, and left rotation. The force distribution patterns and stress concentration areas in all six directions are generally consistent between the U-type and OVCF models. At the L2 vertebra, the U-type model demonstrates the greatest similarity to the OVCF model in the direction of left lateral bending. At the T12/L1 intervertebral disc, no significant differences in force distribution are observed among the four models. At the L1/2 intervertebral disc, the U-type and OVCF models show the closest correspondence in the direction of forward flexion. In the displacement contour diagrams, the maximum displacements of the U-type model are 1.7876 mm (forward flexion), 6.1564 mm (posterior extension), 4.6520 mm (left lateral bending), 6.2224 mm (right lateral bending), 3.4119 mm (left rotation), and 3.1601 mm (right rotation). In the direction of left lateral bending, the U-type model most closely approximates the displacement distribution of the OVCF model.The U-type finite element model constructed in this study more accurately reproduces the biomechanical characteristics of OVCF and demonstrates high applicability.