Empirical and Computational Analysis and Validation for Spatial Stress and Fluid Flow Distributions of Human Knee and Spine Degeneration and Surgical Intervention
[Thesis]
Hassan, Chaudhry Raza
Qin, Yi-Xian
State University of New York at Stony Brook
2020
145
Ph.D.
State University of New York at Stony Brook
2020
Musculoskeletal joint degenerative diseases result from mechanical and biological events in the joint space. Joint soft tissue degeneration has solid and fluid phase mechanical precursors due to changes in the tissue structure and composition. Joint degeneration is a result of stress and fluid flow changes in the soft tissue, and subchondral bone, which leads to imbalance and impairs the normal mechanical equilibrium. The objective of this dissertation research is to assess and evaluate the changes in stress, fluid pressure, and fluid velocity in the degenerated soft tissues of knee and spine joints for disease prediction, mechanical stabilization, and tissue regeneration and repair. Computational finite element (FE) models of human musculoskeletal joints (knee and spine) and avian bone (ulna) were developed and assigned healthy and disease material properties. Human cadaver knee tibial plateau contact pressure was measured under physiological compressive load in the intact and surgically modified proximal fibula osteotomy (PFO) condition. The medial tibial plateau contact pressure decreased while the lateral pressure increased after PFO. Knee FE model was validated with the cadaver values and was used to predict the effect of different surgical levels of PFO. The human spine poroelastic FE model simulated the effect of cartilage endplate degeneration on the intervertebral disc stress and fluid flow. The model predicted increased fluid pressure and decreased fluid velocity in the nucleus pulposus under compression in severe cartilage endplate sclerosis. The FE model of the turkey mid-shaft ulna predicted fluid velocity and pressure changes in intact, bone defect, and scaffold implanted cases under dynamic fluid simulation. These FE models simulated the alterations in stress and fluid flow under musculoskeletal degeneration and surgical intervention conditions. Predictions of the mechanical integrity through these models can assist with in vivo study design and surgical decision making in the musculoskeletal degeneration diseases.