Phase field modelling and simulation of damage occurring in human vertebra after screws fixation procedure

TL;DR

This paper employs a phase-field model to simulate fracture patterns and damage in human vertebrae after pedicle screw fixation, providing insights into post-surgical bone failure and aiding clinical improvements.

Contribution

It introduces a novel phase-field simulation framework for analyzing vertebral damage and fracture patterns post-surgery, considering various screw angles and physiological movements.

Findings

Damage patterns depend on screw insertion angles.

Simulation results align with existing literature.

Insights may improve clinical interventions.

Abstract

The present endeavor numerically exploits the use of a phase-field model to simulate and investigate fracture patterns, deformation mechanisms, damage, and mechanical responses in a human vertebra after the incision of pedicle screws under compressive regimes. Moreover, the proposed phase field framework can elucidate scenarios where different damage patterns, such as crack nucleation sites and crack trajectories, play a role after the spine fusion procedure, considering several simulated physiological movements of the vertebral body. A convergence analysis has been conducted for the vertebra-screws model, considering several mesh refinements, which has demonstrated good agreement with the existing literature on this topic. Consequently, by assuming different angles for the insertion of the pedicle screws and taking into account a few vertebral motion loading regimes, a plethora of numerical results characterizing the damage occurring within the vertebral model has been derived. Overall, the phase field results may shed more light on the medical community, which will be useful in enhancing clinical interventions and reducing post-surgery bone failure and screw loosening.