ON THE CALCULATION OF BONE PORE-WATER PRESSURE DUE TO MECHANICAL LOADING

The purpose of this paper is to calculate the bone fluid pressure in t he lacunar-canalicular porosity of the cortical bone matrix induced by functional mechanical loading and compare it with that induced by the blood pressure differences. This problem reduces to the problem of de termining the bone fluid pressure in a representative axially compress ed osteon which is approximately an annular cylindrical structure. Two available poroelastic approximations, a beam analogy model and a sing le osteon model, are compared and discussed. We find that: (1) at the lacunar-canalicular porosity of a typical load-carrying long bone, nor mal physiological loading induces a bone fluid pressure that is at lea st 40 times larger than that induced by the blood pressure differences ; (2) the solutions of the beam analogy model and the single osteon mo del approach each other as the exterior-to-interior radius ratio of th e osteon approaches one. (C) 1998 Elsevier Science Ltd. All rights res erved.