A comparative study on the mechanical behavior of intervertebral disc using hyperelastic finite element model

BACKGROUND: Lumbar disc herniation may result in excruciating pain due to it being one of the most common diseases related to changes of intervertebral disc (IVD). In order to find a better clinical treatment and prevention scheme for relieving the pain caused by spine degeneration, the mechanical behavior analysis of IVD must be studied. OBJECTIVE: A finite element method (FEM) is used in this study to analyze the mechanical behaviors of healthy and herniated IVD. METHOD: In order to compare the responses of IVD under different loading conditions for the annulus fibrosus of IVD, the hyperelastic and elastic constitutive FE models were used in the FEM. RESULTS: The comparison shows that hyperelastic FE models have a much better capability to describe the mechanical behaviors of the IVD than elastic FE models. It can be found from FE simulation that there was a higher stress concentration at the annulus fibrosus of the herniated disc than the healthy disc. CONCLUSIONS: Higher stress concentration resulted in more damage and ease of bringing out lumbar disc herniation. Numerical examples of FE simulation indicate that the FEM with hyperelastic constitutive model has very good capability for analyzing the mechanical behaviors of IVD.