Clinical Use of Quantitative Computed Tomography–Based Finite Element Analysis of the Hip and Spine in the Management of Osteoporosis in Adults: the 2015 ISCD Official Positions—Part II

doi:10.1016/j.jocd.2015.06.011

Journal of Clinical Densitometry

Volume 18, Issue 3, July 2015, Pages 359-392

https://doi.org/10.1016/j.jocd.2015.06.011 Get rights and content

Abstract

The International Society for Clinical Densitometry (ISCD) has developed new official positions for the clinical use of quantitative computed tomography (QCT)-based finite element analysis of the spine and hip. The ISCD task force for QCT reviewed the evidence for clinical applications and presented a report with recommendations at the 2015 ISCD Position Development Conference. Here we discuss the agreed upon ISCD official positions with supporting medical evidence, rationale, controversy, and suggestions for further study. Parts I and III address the clinical use of QCT of the hip, and the clinical feasibility of existing techniques for opportunistic screening of osteoporosis using CT scans obtained for other diagnosis such as colonography was addressed.

Introduction

This is part II of the report of the QCT task force addressing the evolving clinical use of quantitative computed tomography (QCT) and providing evidence on new and updated official ISCD position statements. This part is dedicated to the clinical value of bone strength calculated by QCT-based finite element analysis (FEA) and introduces new ISCD official positions for FEA. Part I covers the clinical value of QCT of the hip and part III of advanced methods such as voxel- or tensor-based morphometry or statistical parameter mapping. Part III also addresses how to obtain reliable bone mineral density (BMD) information from CT scans acquired to address diagnostic questions other than osteoporosis (i.e., CT scans typically performed without an in-scan calibration phantom used in standard QCT applications).

The clinical use of FEA-based strength measures had briefly been addressed in the earlier position article (1), but since then, a larger number of clinical studies have been published consolidating the evidence and further demonstrating the usefulness of FEA for integrating geometry and local BMD to compute bone strength at the spine, hip, or forearm 2, 3.

Section snippets

Overview of FEA Technology

The finite element (FE) method is routinely used in mechanical engineering to calculate stiffness, strength, as well as internal strains and stresses of complicated structures subjected to external forces. One often cited analogy with bone is an old-fashioned steel bridge because of its striking similarity with trabecular architecture of the vertebrae. Not surprisingly, the FE method has been studied for the past 40 years to simulate the mechanical behavior of bone with increasing fidelity. The

Methodology

A systematic literature search in MEDLINE related to FEA methods using the search clause: (QCT[All Fields] OR CT[All Fields] OR (quantitative[All Fields] AND (computed[All Fields] OR computerized[All Fields]) AND tomograph*[All Fields])) AND (osteoporo*[All Fields] OR osteopen*[All Fields] OR fracture*[All Fields] OR structur*[All Fields] OR strength[All Fields] OR size[All Fields] OR bone[All Fields] OR (cortical[All Fields] OR cortex[All Fields]) OR trabecul*[All Fields] OR cancellous[All

Official Positions for FEA of the Hip and Lumbar Vertebrae

In the following sections, FEA of the spine and hip refers to vertebral or femoral strength, respectively.

ISCD Official Position

Vertebral strength as estimated by QCT-based FEA predicts vertebral fracture in postmenopausal women.

Grade: Fair-B-W

Vertebral strength as estimated by QCT-based FEA is comparable to spine DXA for prediction of vertebral fractures in older men.

Grade: Fair-B-W

Femoral strength as estimated by QCT-based FEA is comparable to hip DXA for prediction of hip fractures in postmenopausal women and older men.

Rationale

In men, standardized

Additional Questions for Future Research

For the measurement of bone strength, FEA is the method of choice. In well-controlled in vitro experiments, progress in CT resolution, image processing, and bone constitutive modeling lead to levels of FEA predictions of hip and vertebral strength that are unreached by densitometric methods. However, because of the random factors associated with falls and adverse loading, this in vitro excellence of FEA will not necessarily translate into spectacular improvement in fracture risk prediction

Acknowledgments

We acknowledge the input of T. Keaveny from OnDiagnostics Inc. who served as external expert.

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2015 ISCD Position Development ConferenceClinical Use of Quantitative Computed Tomography–Based Finite Element Analysis of the Hip and Spine in the Management of Osteoporosis in Adults: the 2015 ISCD Official Positions—Part II

Abstract

Introduction

Section snippets

Overview of FEA Technology

Methodology

Official Positions for FEA of the Hip and Lumbar Vertebrae

ISCD Official Position

Grade: Fair-B-W

Grade: Fair-B-W

Rationale

Additional Questions for Future Research

Acknowledgments

J Clin Densitom

Bone

Med Eng Phys

Radiol Clin North Am

J Orthop Res

Bone

Bone

J Biomech

Bone

Bone

Bone

Bone

Bone

Bone

Bone

Bone

Bone

Bone

Bone

Bone

Med Image Anal

J Biomech

J Biomech

Bone

Bone

Bone

J Mech Behav Biomed Mater

J Biomech

J Biomech

Bone

J Biomech

J Biomech

Med Eng Phys

Spine J

J Biomech

Metabolism

J Clin Densitom

Bone

Bone

Bone fragility and imaging techniques

Clin Cases Miner Bone Metab

Advanced CT based in vivo methods for the assessment of bone density, structure, and strength

Curr Osteoporos Rep

Biomechanical computed tomography-noninvasive bone strength analysis using clinical computed tomography scans

Ann N Y Acad Sci

Bone strength: current concepts

Ann N Y Acad Sci

QCT-based finite element models predict human vertebral strength in vitro significantly better than simulated DEXA

Osteoporos Int

Robust QCT/FEA models of proximal femur stiffness and fracture load during a sideways fall on the hip

Ann Biomed Eng

2015 ISCD Position Development Conference
Clinical Use of Quantitative Computed Tomography–Based Finite Element Analysis of the Hip and Spine in the Management of Osteoporosis in Adults: the 2015 ISCD Official Positions—Part II