A model of fluid injection into the spinal disc

作者：Ngwa Matthias; Agyingi Ephraim^*

来源：Applied Mathematical Modelling, 2012, 36(6): 2550-2566.

DOI：10.1016/j.apm.2011.09.039

• Intervertebral disc
• Fluid injection
• Intradiscal pressure
• Fibre displacement

This paper presents an analytical model of the stressstrain response of intervertebral disc to fluidinjection. The disc has nonlinear properties and collagen fibres play a significant role in sustaining strain. Each fibre is modeled as a flexible, helical string inclined at similar to 30 degrees to the horizontal plane. The tensile stress in the fibres is obtained from a nonlinear stressstrain law that has been determined by experiment. An asymptotic approximation of the model equations based on the ratio of the fluid injected to the initial volume of fluid in the disc is developed and its solution obtained. Some quantitative predictions are made by considering a hypothetical value of the amount of fluid injected and some material values of discs at different levels of the spine. Numerical simulations show that the model compare reasonably well with some experimental observations for discs of the lumbar region.

• 出版日期2012-6