All right, thanks, Nicole. Disclosures are also found in the program. So we know that, or we think that high levels of physical activity during skeletal maturation is the commonly accepted theory as to what grows the CAM morphology in the proximal femur. So this is the proximal femoral physis. We think if this is continually stressed during adolescence, the physis does not close, but rather turns the corner and grows down the anterolateral femoral neck to create a CAM morphology. This is a sequential MRI from a hockey player in Bern, Switzerland, courtesy of Klaus Siebenrock. You can see that the anterolateral head-neck CAM develops slowly. This is between the ages of 13 and 16 during a highly active hockey adolescent career. The impact of physical activity and loading on acetabular morphology is less understood, as well as sport choice and high levels of physical activity may also contribute to the role of acetabular development. The purpose of this study was to evaluate the role of activity level and sport type on both proximal femur and acetabular morphology in late adolescence. We use the Iowa Bone Density Study, which is directed by our Department of Dentistry. It's funded by the NIH. It longitudinally follows kids between the ages of 17 and 23, or in late adolescence, with a DEXA scan surveys. There's very detailed sport data within them, and athletes have played more than two seasons of high school or college sports. They were grouped into power sports, non-power sports, and non-athletes, according to Ward et al. This is an example of some measurements that we were able to obtain from these studies. Lateral center edge angle, alpha angle, the 12 o'clock position, and also head-neck offset ratio. The 12 o'clock position is where we made all of our alpha angle measurements, and this is important because this is the position that predicts osteoarthritis long-term. It's also been associated with symptoms and loss of internal rotation when a CAM developed and expands to 12 o'clock. Power sports and non-power sports were defined according to this Ward et al. study. We analyzed 317 individuals. We found no significant differences in baseline characteristics, and lateral center edge angle did not correlate with activity level or sport type in any of our analyses. We found that higher activity scores predicted higher alpha angle between the ages of 17 and 23, and lower head-neck offset ratio. So this corroborated some earlier findings that sport type and loading does predict development of CAM morphology. This is an example of a non-athlete. Between the ages of 17 and 23, you can see no real change in the AP alpha angle at 12 o'clock. Conversely, this is a high school and a collegiate football player who had an alpha angle in the low 40s or 50s at age 17, and by 23, he was near 70 degrees. These are the groups of power sport athletes in green, non-power sport athletes in blue, and non-athletes in black, and you can see that the athletes have increasing alpha angles through this late adolescent period, and these findings are most strongly observed in power sport athletes. And if you look at this data, adjusting for sex and age, a power sport athlete is three times more likely to develop an alpha angle greater than 55, and twice as likely to meet the threshold of FAI using a head-neck offset ratio measurement. So high school participants in power sports are more likely to develop a CAM morphology, and this correlates with activity levels, and there's no association between activity level and lateral center edge angle. This corroborates some findings from the burn group. This is a prospective study of hockey players between the ages of 13 and 16 that demonstrated significant correlations between activity level and CAM development in this group, but our findings suggest that even after the age of 16, there is probably still some changes in the femoral head-neck junction that can be assessed. So increased sports participation, three-fold likelihood to develop a CAM lesion, unrelated to acetabular morphology, which probably develops earlier, and further study into sports diversification specialization may be warranted. Thank you.

physical activity

CAM morphology

proximal femur

skeletal maturation

acetabular morphology