Development and Validation of Instrumented Synthetic Mechanical Analog Lumbar Spine

DESCRIPTION (provided by applicant): The intended outcome of this SBIR proposal is a commercialized physical model of the lumbar spine (S1 - T12) that will consist of synthetic, normal or osteoporotic vertebrae, intervertebral discs, ligaments and facet j oints. The anatomical and mechanically qualified analogue lumbar spine model will be engineered to provide clinically relevant measurements of disc pressure and facet joint loads from embedded instrumentation. This technology will create a standardized e xperimental spine model with low inter-specimen variability that can be used to elucidate fine differences in spinal implants and surgical procedures that would otherwise be difficult to discover through tests on largely variable cadaver spines. The overa ll objective of Phase II is to commercially manufacture and validate a synthetic mechanical analogue spine model with embedded instrumentation. Previous work from Phase I resulted in the transfer of current research concepts to create commercially manufac tured mechanical analogue soft tissues for the lumbar spine and anatomical vertebrae. PRL demonstrated the ability to control and reproduce analogue tissue specimens, however difficulties were encountered with environmental sensitivity of the urethanes af fecting the mechanical properties. Quality control measures will be implemented in manufacturing to ensure reproducible and reliable mechanical properties are achieved. Assembled models were evaluated for their mechanical performance in bending and compr ession. Results indicate that more iterative steps are needed to fine-tune a few parameters of the assembled model. Phase II will continue the work from phase I to; manufacture synthetic vertebrae designed to have mechanical behaviour similar to normal a nd osteoporotic vertebral bone; assess the fatigue performance of the analogue spine model; develop a computational model; develop simple, reliable and cost effective disc pressure and facet joint load measuring techniques and lastly, qualify the manufactu red model with embedded instrumentation and qualify the instrumented model for use in medical device quasi-static testing by comparison to human cadaveric specimens. The PI and co-investigators envision that these models can be used in a variety of capaci ties for spine research and product development. The models will aid in understanding the effects of surgical procedures and implants on potential patient outcomes. An analogue spine model will also be an efficient way to perform biomechanical tests and product development.