Finite element modeling of the growth plate in a detailed spine model

Very few computer models of the spine integrate vertebral growth plates to investigate their mechanical behavior and potential impacts on bone growth. An approach was developed to generate a finite element (FE) model of the lumbar spine and their connective tissues including the growth plate, which allowed a personalization of the geometry based on patients' bi-planar radiographs. The geometrical validation was performed by deforming meshed vertebrae to reference vertebral specimens and comparing geometrical indices. No significant difference was found between the measured parameters, with errors under 1% in 83% of the geometrical parameters. Mechanical validation was done by simulating loading cases on a functional unit representing experimental testing on cadaveric spines. The flexibility of the functional unit remained between expected ranges of motion, but was more linear than experimental data. The mechanical behavior of the growth plate was evaluated under various loading cases: greater stresses were located in the proliferative zone for the different spinal loading cases tested. This modeling approach is a useful tool to study the effect of mechanical stresses on bone growth.