Tissue Injury and Effects of Applied Vibration on the Intervertebral Disc
Author: Geoffrey Desmoulin
Publication: University of Calgary
It is thought that disc degeneration can cause spine related pain. New treatments acting at cellular levels in the intervertebral discs (IVD) may offer potential to improve long-term disc health. Hence, optimized loading that induces positive cellular changes in the disc may improve disc health delaying the onset of degeneration, thus delaying the onset of pain. This dissertation evaluates and improves a vibration based spinal intervention called the Khan Kinetic Treatment (KKT) while describing some of its mechanisms of treatment of the intervertebral disc. Objectives of this study are to: 1) test effects of vibration on disc biosynthesis prior to device modifications (KKT_v1); 2) determine vibration conditions that are most effective in positively altering IVD gene expression; 3) implement findings from objective 2 by modifying the spinal intervention (KKT_v2) and repeating tests; and 4) design, build, validate, and experiment with a novel bioreactor so that other tissues may be targeted. It could be concluded that the un-modified interventions (KKT_v1) vibration loading profile did not fall within the influential range that affects the cells of the bovine IVD. Objective 2 results showed that expression of certain extracellular matrix genes were significantly up regulated with specific vibration loading patterns, indicating a potential therapeutic stimulus (10 min. total duration of an equal mix of 16 Hz and a 50-80 Hz frequency sweep at a minimum of 0.4 g amplitude). Objective 3 had KKT_v1’s firmware edited to drive the new frequencies found to be most effective in objective 2 making KKT_v2; results of objective 3 showed that expression of certain extracellular matrix genes were significantly up regulated when vibrated with the modified intervention (KKT_v2) indicating a potential therapeutic stimulus of the intervention itself. Objective 4 results confirmed the positive influence of mRNA expression with the new bioreactor by utilizing the optimal vibration patterns identified in objective 2. iv This research has moved past the proof of concept stage as it has been shown that specific vibration conditions (10 min, 16 & 50-80 Hz, 0.4g) can influence the expression of cell genes in the IVD. The novel bioreactor built as a result of chapter 4 allows us to test other tissues, while mimicking in-vivo conditions. This information could be used to construct future experiments in protein expression or in-vivo MRI studies of human IVD.