Posterior Spinal Fusion Hardware for Patients with Poor Bone Quality

Osteoporosis is a disease involving a decrease in bone mass and a resultant increased risk of bone fractures. Vertebral fractures are the most common type of fracture in patients with osteoporosis. Spinal fusion is the process by which two or more vertebral levels are joined into a single bone mass to restore stability to a spine that has been compromised by trauma or disease. Fusion is accomplished through implanted hardware, including pedicle screws, rods, plates, and cages used to make a temporary bridge between vertebrae to stabilize the spinal column for healing. The overall goal of the project is to design, fabricate, and test functional prototypes of implants and instruments for a spinal fixation system that is more successful than currently existing spinal fixation systems for patients with osteoporosis. High-resolution computed tomography (CT) scans were conducted and analyzed using medical image processing software. This information was used to determine the appropriate sizing and degree of geometric accommodation needed to apply the plates to the spine. The performance and quality of the design will be validated in a mechanical testing laboratory following ASTM standards to ensure proper quality and workmanship. The expected benefits of the project are a safe, simple, easy to use device to aid the spine surgeon in the treatment of patients with reduced bone quality and that will reduce the incidence of post-operative complications. Although testing of the device did not lead to the expected results, much was learned in the process that can be used to refine the device into a viable product.

A project submitted to the Department of Mechanical Engineering in partial fulfillment of the requirements for the B.S. degree. Department of Mechanical Engineering ME 494