[Simulation through the method of finite element of alendronate in a model of bone remodeling based on damage mechanics].

Abstract

Mechanical loads are one of the main factors that affect bone remodelling process. This phenomenon is widely applied to the study of prosthetic replacement, for example hip prosthesis. Elderly people are the most common patient to receive a hip replacement surgery. Alendronate is a drug that is being used to increase bone mineral content in patients with poor bone quality. This work uses a mechanical model based on damage mechanics, which considers bone's porosity as the damage variable, a mechanical stimulus associated thermodynamically to this variable, a damage criterion and an evolution damage law. Our approach simulates the degree of mineralization changes as well as the decrease of BMU activation frequency due to Alendronate doses. The biological changes generated by the drug directly affect the damage's evolution law. As a first approach the two biological parameters to be modeled are the surface of remodelling as well as the degree of mineralization (ash fraction) of the bone. Results show a good correlation with experimental data from alendronate's treatments for short term simulations (1-2 years).