1Division of Anatomy, The Ohio State University, 2Department of Anthropology, The Ohio State University
Friday All day, Clinch Concourse
Rib fractures can affect morbidity and mortality in elderly individuals and the risk of their occurrence increases significantly with age. Clinical diagnoses of bone fragility often fail to measure the contribution of poor bone quality. An inefficient remodeling process in aging individuals results in disrepair of microfractures, allowing their accumulation to reach harmful levels. While it is established that microfractures contribute to catastrophic bone failure, it is unknown to what extent they exist in human ribs and their role in determining bone quality. Additionally, the loads habitually applied to the rib during respiration are difficult to determine and therefore absent from many discussions on adaptive responses to loading. The objective of this research is to explore individual variation in microfractures which accumulate in vivo in elderly ribs. Samples from sixth rib pairs were removed from ten elderly cadavers, stained en bloc in Basic Fuchsin Hydrochloride, and transverse thin-sections prepared. A two-way mixed model analysis of variance (ANOVA) reveals significant differences in microfracture accumulation between individuals, but not within (left vs right rib). Only insignificant differences were found in crack location, with slightly more microfractures accumulating in the cutaneous cortex. These findings suggest that microfracture accumulation in the elderly has the potential to contribute to differential fragility. Additionally, based on crack distribution, the priority may be to preferentially maintain a higher bone quality in the pleural cortex. Knowledge of the mechanisms involved in bone quality deterioration is vitally important to establish methods to combat fragility fractures in the high-risk elderly population.