Presenter: Megan Stickley
Authors: Megan Stickley, Danni Porter, Anton Bowden
Faculty Advisor: Anton Bowden
Institution: Brigham Young University
Human vertebral endplates are important gatekeepers of nutrient flow between the vasculature in the spinal vertebrae and the avascular spinal discs. These endplates are made up of porous bone that transports nutrients through means of pressured fluid flow. In order to test the hydraulic permeability (resistance to fluid flow of a porous material) of both human and artificial vertebral endplates being developed in our laboratory, it was necessary to replicate the conditions that endplates experience in the body. Specifically, by developing a device that could safely pressurize a spinal disc fluid analog through endplate samples at 200 psi while being held in a stable position. The fluid that passes through the endplates from the disc is a buffered saline solution, with additional nutrients, ions, and cellular products. Following a structured design process, a custom vertebral endplate hydraulic permeability tester was designed and manufactured. A hydraulic pump was used to pressurize the spinal disc fluid analog in an appropriately pressure-rated 4-inch diameter polyvinyl chloride (PVC) pipe, using a gasket-sealed pressurizing cylinder. The piping was then connected so that the fluid could travel up through the sample and out a section of tubing to be collected and measured. Pressure in the piping directly prior to the sample was measured through means of an integrated pressure gauge. Vertebral endplate and CICNT samples were held in place by a custom designed silicone flange, which was cast using a 3-D printed mold. The silicone flange was compressed into position using adjacent PVC pipe threads.