Effect of chronic centrifugation on the cross-sectional shape of long bones in dogs.

Alterations in cross-sectional shape at midlength of the femur, tibia, and humerus of 16 male Beagle dogs exposed for 6 months to either 2.1 g or 2.6 g by centrifugation were analysed by the area moment correlation coefficient, as defined by AMTMANN and POTULSKI (1981). As shown by variance analysis the cross-sectional shape differences between bones are highly significant, while the treatment effects are only significant at a 5% level. While the femur and the tibia are almost alike in the shape of their whole sectional area and cortical surface, they differ in the shape of their marrow cavity. The most oval cross sections were found in the humerus. In femur and humerus the shape of the whole sectional area, the marrow cavity and the cortical surface tend to be more oval in the centrifuged animals than in the controls. In the tibial cross sections the opposite is the case. A significant interaction "Gravity X Bone" was found for the shape of the marrow cavity.