Response of trabecular bone at the distal femur to changes in loading with the development of the bicondylar angle
Open Access
- Author:
- Conner, Benjamin Charles
- Area of Honors:
- Anthropology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Timothy Michael Ryan, Thesis Supervisor
Timothy Michael Ryan, Thesis Honors Advisor
Philip L Reno, Faculty Reader - Keywords:
- trabecular
bone
femur
asymmetry
anthropology
bicondylar
angle
distal
metaphysis
epiphysis
condyle
bipedalism - Abstract:
- The femoral bicondylar angle develops during ontogeny in response to changes in loading associated with the onset and maturation of bipedal walking. The magnitude and orientation of loads at the knee joint change significantly during development as the bicondylar angle increases and then stabilizes. The goal of this study is to assess the trabecular bone structural changes of the distal femur in relation to the developing bicondylar angle with the expectation that bone structure will reflect a shift in load magnitude and orientation at the knee during ontogeny. Three-dimensional trabecular bone architecture in the distal femur was quantified from microCT data in 56 individuals from the Norris Farms #36 archaeological skeletal collection. Asymmetry of this trabecular bone architecture between the medial and lateral condyles was quantified by measuring the following morphometric measures: bone volume fraction (BV/TV), degree of anisotropy (DA), trabecular separation (Tb.Sp), trabecular thickness (Tb.Th), and connectivity density (Conn.D). Bicondylar angle was quantified by measuring the angle between the long axis of the bone and the distal femoral metaphyseal and epiphyseal margin. Individuals ranged in age from neonate to adult. We found no significant asymmetry in BV/TV, Conn.D, Tb.Sp, or Conn.D in the metaphysis for all age groups. These results suggest that trabecular bone structure in the distal femoral metaphysis does not reflect changes in load magnitude. However, a trend toward lateral dominance in BV/TV that correlated with the development of the bicondylar was observed, which could be explained by the actions of the lateral collateral ligament.