Okay, next talk is Biomechanical Finite Element Analysis of the Developing Cranio-Cervical Junction by Dr. Broffman. Good afternoon. My subject is the biomechanical analysis of the developing CCJ using finite element modeling. I have no relevant disclosures. First off, I'd like to thank my co-contributors, the two people on the left, Renshin Funsock and Ben Ellis are from the Department of Biomechanics at the University of Utah. And Andrew Daly is one of my adult spine colleagues, is on the right-hand side, is from the University of Utah as well. So the biomechanical properties of the developing cranio-cervical junction are poorly understood. I think we all would agree on that. It's assumed that there's age-dependent maturation processes that occur within the bony structures of the CCJ. We've already published that there's material property differences and soft tissue differences, but little data supports this notion. So we used finite element modeling to explore this hypothesis. We took three validated finite element models of normal pediatric cranio-cervical junctions in a 13-month-old, a 10-year-old, and a 14-year-old, and compared it to a normal finite element model in the 26-year-old subjects. We applied a moment of 0.1 newton-meters, which is a more pediatric type of force, and another one of 1.0 newton-meters, which is a more adult type of force, to the occiput of each model, inflection and extension, rotation and lateral bending. And each one of them had appropriate, identical material properties. This is what these models look like. Each one takes approximately six months to create. Here it is inflection. This is here in rotation. This is the 13-month-old applying pediatric forces. So here's a summation of our data. And to break it down in just a couple of seconds, what we see is an age-dependent increase in stiffness. As subjects get older, you typically see the, or you definitely see the increase in stiffness in the pediatric forces applied. And you see the same phenomenon with the adult forces applied. When you focus in on the pediatric flexion curves, which is probably the most important one, it looks like we have good correlation between the 13-month-old finite element data and the 11-month-old corresponding catabaric data. But the corresponding curves between the 10- and 14-year-old curves and the 12- and 14-year-old catabaric data is not so good. However, our 26-year-old finite element data compared favorably to the catabaric data that's been previously published, plus the age-dependent decrease in stiffness that you see here. These are the same results in tabular format. You can see, as patients get older, the stiffness increases in both models. And again, the good correlation in our infant-type model or toddler model and the less correlation in the adolescent models. So we feel that this type of technique appears to demonstrate that geometrical scaling and bony maturation is important to the overall development of the craniocervical junction. It corroborates data found in catabaric spine models. Obviously, we need to do further work to explain the discrepancies in some of the catabaric and finite element force data. But we think this is a viable way to help understand the developmental biomechanics in the craniocervical junction. Thank you. We have some time for some questions.

biomechanical finite element analysis

developing cranio-cervical junction

age-dependent maturation processes

finite element modeling

stiffness increase