An approach for time‐dependent bone modeling and remodeling—application: A preliminary remodeling simulation

TLDR

A time‑dependent theory for bone modeling and remodeling driven by daily loading history was introduced in a companion paper. The study aims to predict bone density distribution in the adult proximal femur under normal loading using the theory. The model adapts internal bone structure to altered loading while keeping external geometry fixed, comparing linear and trilinear remodeling laws. Finite‑element simulations starting from a homogeneous bone produced a normal‑appearing density distribution; reducing loading caused regional atrophy, while restoring normal loading increased bone mass but altered distribution, confirming the theory’s applicability and supporting the hypothesis that stress‑related mechanisms drive both morphogenesis and functional adaptation.

Abstract

Abstract In a companion paper, we presented a time‐dependent theory for bone modeling and remodeling in response to a daily loading history. This paper represents a preliminary attempt to use the theory to determine the distribution of bone density within the adult proximal femur under an assumed normal loading history. Subsequent functional adaptation of the internal structure due to changes in the loading history are then determined. Throughout this preliminary study, the external geometry of the proximal femur is considered to be fixed, i.e., changes in the external shape are neither stimulated nor allowed. Linear and trilinear (dead‐zone nonlinearity) rate remodeling laws were compared. Computer emulations using two‐dimensional finite element models were successful in creating a normal‐appearing distribution of bone tissue when remodeling was initiated from a solid structure of homogeneous bone density. Subsequent reduction in the loading history caused regional bone atrophy. Reinstatement of the normal loading history caused a generalized increase in bone mass but resulted in a slightly different bone distribution than was calculated for a constant loading history. These results demonstrate the utility of the remodeling theory and are consistent with the hypothesis that similar stress‐related phenomena are responsible for both normal morphogenesis and functional adaptiation in response to changes in the bone loading.