VISCOELASTIC CHARACTERIZATION OF RABBIT NUCLEUS PULPOSUS TISSUE IN TORSIONAL CREEP

摘要: Recently, molecular therapy approaches have been shown to favorably alter the course of intervertebral disc degeneration (IDD) in a rabbit model. Typical experimental outcome measures for model IDD include MRI, x-ray, histology, and gene expression. Biomechanical function is another desirable parameter through which compare treatments, although this difficult due limited availability data small animal models. In current study, nucleus pulposus tissue was taken from healthy tested torsional creep establish database behavior future use assessing functional efficacy treatments IDD. Nucleus excised L5-L6 disc, mounted between cone plate an AR1000 Rheometer, various experiments were performed. Several models fit modeling analyses conducted. Of compared, Andrade provides most reliable extrapolation. It appears that nonlinearly viscoelastic since it does not adhere Boltzmann superposition principle. A nonlinear constitutive model, derived used predict strain obtained at higher levels stress, consistent prediction results. The application degenerated NP expected result altered parameters - thus providing quantifiable, benchmarks success treatment