Finite element analysis of fluid-structure interaction model of lumbar spine and cerebrospinal fluid

A finite element model was created to analyze the mechanical response of the lumbar spine, dura mater, and cerebrospinal fluid (CSF) under fluid-solid coupling. This model provides a theoretical basis for studying the impact of CSF flow on the spine. The method utilizes CT scans of patients with Lenke3 scoliosis and employs medical image processing and 3D modeling software to create a solid-fluid coupling model of the lumbar spine's CSF. The simulation operations involve finite element software, which includes meshing, material property determination, contact definition, and boundary condition setting. The simulation results showed the distribution of stress in the dura mater and 5 lumbar vertebrae. The outlet position for CSF flow typically corresponded to the location of the highest velocity vector. At flow rates of 5, 8, and 12 cm/s, the corresponding results were 16.23, 25.32, and 47.2 cm/s. The maximum Von Mises stress values for the dura mater at three flow rates were 1.634x10^-3 Mpa, 3.699x10^-3 Mpa, and 7.456x10^-3 Mpa. The force of CSF flow on the dura mater is transmitted to the lumbar vertebrae, resulting in varying Von Mises stress magnitudes and distributions across each segment. The L2 segment experiences the highest stress levels at all three flow rates, with maximum Von Mises stress values of 1.598x10^-4 Mpa, 3.596x10^-4 Mpa, and 7.18x10^-4 Mpa on the lumbar vertebrae. As the CSF flow rate increases, so do the maximum velocity vector value at the outlet position and the Von Mises stress values on the dura mater and lumbar spine. The CSF flow rate can impact lumbar bone cell proliferation.