Construction of Fracture Line Maps and Finite Element Biomechanical Analysis of Lumbar Vertebral Compression Fractures

Objective To construct three-dimensional fracture line maps for L1-L5 lumbar vertebral compression fractures and, integrated with finite element analysis, reveal their underlying biomechanical mechanisms, thereby providing a foundation for precise clinical diagnosis and treatment. Methods A retrospective analysis was conducted on CT imaging data from 220 patients with lumbar compression fractures admitted between February 2022 and August 2025. Fracture line maps were generated using three-dimensional reconstruction and spatial registration techniques. Based on CT data from a healthy volunteer, individualized finite element models of isolated L1-L5 vertebrae were established. All methods were performed in accordance with relevant guidelines and regulations. These models were used to simulate and analyze stress distribution under five physiological loading conditions: vertical standing, flexion, extension, left lateral bending, and left axial rotation. Results Fracture lines were predominantly concentrated in the anterosuperior region of the vertebral body (cubes UL-1, UM-1, UR-1). The spatial distribution pattern of fracture lines from L1 to L5 exhibited a transition from “anterosuperior concentration” to “multi-directional dispersion.” Finite element analysis revealed that under vertical loading, stress concentrated in the anterosuperior portion of the vertebral body. For all vertebral levels, the peak stress was highest during flexion. Notably, the anterosuperior region demonstrated persistent high-stress concentration across all simulated postures. Conclusion The anterosuperior region of the lumbar vertebral body is identified as a “vertebral stress core zone,” representing a high-risk area for compression fractures. The synergistic combination of fracture line mapping and finite element analysis systematically elucidates the fracture mechanism from both morphological and biomechanical perspectives.