FINITE ELEMENT ANALYSIS OF TISSUES WRAPPING AROUND THE KNEE JOINT OF OSTRICHES (STRUTHIO CAMELUS)

Chadwick, K P and Allen, V R and Hutchinson, J R (2015) FINITE ELEMENT ANALYSIS OF TISSUES WRAPPING AROUND THE KNEE JOINT OF OSTRICHES (STRUTHIO CAMELUS). FASEB JOURNAL, 29 (1).

Full text not available from this repository.

Abstract

Mechanical stimulation is accepted to play some role in the development of sesamoid bones, however with great variability in occurrence, it is not yet clear how significant this role is and what specific loading environment fosters or hinders growth. The patella is the most familiar sesamoid bone, yet there is still great diversity of presence and morphology of patellae across vertebrates. Ostriches are unusual among ratites, and indeed among most other animals, in that they have a double (proximal and distal) patella as opposed to a single bone. Our objective was to estimate how the patellae of an ostrich are loaded in order to better characterize how sesamoid bones develop in response to mechanical stimulation. We scanned an adult ostrich using computed tomography and magnetic resonance imaging. We digitally segmented and co-registered the scans to create a single three-dimensional model of all of the bones and tissues surrounding the knee joint. This model was used to create multiple two-dimensional and three-dimensional finite-element analysis (FEA) studies of the loading on the tissues surrounding the knee joint. The results of our anatomical and FEA studies suggest that the areas where the patellae are present in adults correlate well with areas which shear strain would occur in the tissue wrapping around the joint. Based on these preliminary results, we conclude that shear stress, due to steep surface gradients near the femoral condyles, is a good indicator of potential for sesamoid development in ostriches. Further studies, especially across ontogeny, are necessary to understand the relationship of stress and sesamoid bone development.