Nanoindentation of osteonal bone lamellae

Variations in Young’s modulus of individual lamellae around a single bone osteon have been measured in three orthogonal planes by nanoindentation. The objective of these measurements was to establish a correlation between the mechanical properties and the microstructure of the osteonal lamellae. When indentation was performed in a plane perpendicular to the osteon axis (OA), the modulus of the lamella closest to the canal appears to be higher than the modulus of all other lamellae. No such difference was observed in planes parallel to the OA. However, in the parallel planes, an unexpected asymmetry in modulus was detected on opposing sides of the canal, potentially supporting the validity of the rotated plywood structure model of bone lamellae. Finally, based on the experimentally measured Young’s modulus values, most osteonal lamellae appear to exhibit structural anisotropy.

► A correlation between Young’s modulus and the microstructure of osteon lamellae is studied.
► The modulus of individual osteonal lamellae was measured in three orthogonal planes.
► In the axial direction the modulus of the 1st lamella is higher than for all other lamellae.
► In the radial direction a difference in modulus exists between both sides of the canal.
► The results appear to support the validity of the rotated plywood structure model of bone lamellae.