Osteoporosis pharmacological treatment evaluation through femoral biomechanical response using DXA-based 3D Finite Element Modelling

Abstract

Osteoporotic hip fractures are one of the most severe an individual can suffer due to their high mortality rate. There are pharmacological treatments such as Alen-dronate (AL), Denosumab (DMAB), and Teriparatide (PTH) that help on reducing these fractures. Depending on their mechanism of action, they improve the bone mineral density (BMD) of either the cortical or the trabecular bone. Dual-Energy X-ray absorptiometry (DXA) is used to measure this parameter and quantifies bone improvement with these therapies. Several studies had combined Finite Element (FE) models with medical images to estimate fracture prediction. Yet, there is no evidence of using such methodology to study drug effectiveness by assessing the

biomechanical response of the bone. Thus, the aim of this study is to evaluate dif- ferent osteoporotic treatments using DXA 3D FE modeling and analyze the Major

Principal Stress (MPS) and Major Principal Strain (MPE). A cohort of 155 osteo- porotic patients were divided into four groups AL (n=54), DMAB (n=33), PTH

(n=31), and a control group designated as NAIVE (n=37). Two DXA acquisitions

were provided before and after 1-2 years of taking the medication. A side-fall simu- lation was evaluated with a patient-specific force applied in the femoral head where

the distal bone was fixed, and the trochanter was constrained in the direction of the force. The biomechanical parameters: volumetric BMD (vBMD), MPS, and MPE were analyzed by tissue (cortical or trabecular), zone (neck or trochanter), and by its combination. Results showed decreasing strain when vBMD increases, indicating that the bone deforms less due to the reinforcement of its structure. DMAB had the highest outcomes, while the trabecular bone and the trochanter area were the most reinforced. Overall, this study suggests that DXA 3D finite element models might be a valuable tool in clinical practice for evaluating pharmacological treatment for osteoporosis.