# Inelastic mechanical descriptors for osteoporotic hip fracture discrimination with 3D-DXA-based nonlinear finite element models

## TL;DR

This study shows that 3D-DXA models combined with mechanical analysis can better predict hip fracture risk compared to traditional bone density measurements.

## Contribution

The study introduces inelastic mechanical descriptors derived from 3D-DXA-based finite element models to improve hip fracture discrimination.

## Key findings

- Strength and trabecular volumetric bone mineral density equally discriminated fracture and control subjects.
- Residual displacement from plastic strain improved fracture discrimination when combined with strength.
- 3D-DXA and finite element modeling offer better fracture assessment than traditional DXA methods.

## Abstract

Dual-energy X‐ray absorptiometry (DXA) is the gold standard for diagnosing osteoporosis. Advances in 2D‐3D modelling to generate patient-specific 3D‐DXA models out of DXA images enable accurate volumetric representations of the femur, with potential for fracture risk prediction when combined with finite element (FE) analyses. This study evaluates the ability of 3D‐DXA-based FE models to discriminate hip fractures under side-fall loading.

We used a retrospective case‐control study including 128 women, 64 of whom suffered a hip fracture. Mechanical descriptors, including strength, nonlinear deformation, residual displacement, and energy absorption under elastic‐plastic assumptions, were derived from force-displacement curves.

The area under the receiver operating characteristic curve (AUROC) showed that strength and trabecular volumetric bone mineral density (vBMD) equally discriminated between fracture and control subjects. Residual displacement due to plastic strain accumulation at failure emerged as a key descriptor which, when combined with strength, significantly improved fracture discrimination (ΔAUROC = 0.11 vs. areal bone mineral density (aBMD); ΔAUROC = 0.08 vs. trabecular vBMD).

These findings highlight the potential of 3D-DXA and FE modelling to improve fracture assessment within current DXA-based clinical workflows.