The ultim ate tensile strength of isolated osteon specimens has been measured in its relationship to the process of calcification.
The specimens were prepared using 30-50 micra thick longitudinal sections from femoral shafts and applying a personal technique of dissection. The measurements were taken on units giving a good guarantee as regards optical orientation and homogeneity.
The tensile strength of osteons is significantly greater in dry tested samples than in wet ones. The osteons with a marked longitudinal arrangem ent of the fibrebundles in successive lamellae show a higher tensile strength. The degree of calcification does not induce any significant variation of the ultim ate tensile strength in osteons showing the same structure in the orientation of the collagen fibre-bundles. There is no decrease in tensile strength in osteons with advancing age. Human and ox osteons have the same tensile strength.
The view th at the collagen fibres of the matrix are essential in determining some mechanical properties of bone, is strongly supported by the fact th at the tensile strength reaches the same m agnitude both in calcified and decalcified osteons.