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cancellous bone, development, knuckle-walking, locomotion, Pan troglodytes
Abstract:
Objectives: Trabecular bone structure is known to be influenced by joint loading during life.
However, many additional variables have the potential to contribute to trabecular bone struc-
ture of an adult individual, including age, sex, body size, genetics, and overall activity level. There
is little research into intraspecific variability in trabecular bone and ontogeny of trabecular bone
structure, especially in nonhuman primates.
Materials and methods: This study investigates trabecular structure in adult and immature chim-
panzees from a single population using high-resolution microcomputed tomographic scans of
the proximal humerus, proximal femur, and distal tibia. Trabecular bone volume fraction
(BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular spacing (Tb.Sp), and
degree of anisotropy (DA) were quantified in specific regions of adult and immature chimpan-
zees, and color maps were generated to visualize the distribution of BV/TV throughout the joint
in the metaphysis of immature specimens.
Results: The results demonstrate that variability in adult trabecular structure cannot be
explained by sex or body size. During ontogeny, there is a general increase in trabecular BV/TV
and Tb.Th with age, and ratios of trabecular parameters between the fore- and hindlimb may be
consistent with locomotor transitions during ontogeny.
Discussion: Variation in trabecular morphology among adult individuals is not related to sex or
body size, and the factors contributing to intraspecific variability, such as overall activity levels
and genetic differences, require further investigation. Trabecular ontogeny in chimpanzees dif-
fers from humans in some respects, most notably the absence of a high BV/TV at birth.
