Exploring the impact of mechanical stimuli on growth plate morphology and trabecular adaptation: A finite element approach.

BACKGROUND

This research investigates how trabecular patterns affect growth plate morphology, focusing on shape, trabecular patterns, and ossification bridges. By studying mechanical adaptations, we propose a new methodology to model endochondral growth and bone remodeling, applicable to clinical cases involving growth abnormalities or growth plate diseases.

METHODS

We developed a finite element model that integrates bone remodeling with an endochondral ossification law. The osteogenic index was used to impose a strain rate tensor, capturing growth from chondrocyte hypertrophy and proliferation in the growth plate. Then an examination was performed of the mechanical influence of trabecular structures on growth plate development and ossification through qualitative topology comparisons and statistical analysis of shape parameters affecting bone formation. Validation was conducted using medical images and μ-CT scans. The model was calibrated with a benchmark case, adjusting growth plate shape and thickness, and then applied to a hip dysplasia case and tibial growth.

FINDINGS: Growth plate adapts its shape in response to the local mechanical environment and this has implications for growth plate closure. Unlike previous models treating the environment as a continuum, our model assessed localized load transmission via trabecular groups. Morphological changes in the growth plate and nearby bone adaptation help withstand shear stress, increasing bone density in specific regions, the most significant parameters being growth plate thickness and period of oscillations. A response surface and Pearson coefficient analysis show that the thickness and amplitude of the growth plate have the most significant effect on the bone density in the vicinity of the growth plate.

CONCLUSIONS

This new model has the potential to advance the management of medical conditions such as slipped capital femoral epiphysis, Sever's disease, and interventions like epiphysiodesis. This research may lead to improved diagnostic tools and therapeutic strategies for treating growth plate-related disorders.