proximal-cadaveric-femur-preparation-for-fracture-strength-testing

Proximal Cadaveric Femur Preparation for Fracture Strength Testing and Quantitative CT-based Finite Element Analysis

Cadaveric fracture testing is routinely used to understand factors that affect proximal femur strength.  Because ex vivo biological tissues are prone to ...

method-instrumented-fixture-for-femoral-fracture-testing-sideways

Method and Instrumented Fixture for Femoral Fracture Testing in a Sideways Fall-on-the-Hip Position

Mechanical testing of femora brings valuable insights into understanding the contribution of clinically-measureable variables such as bone mineral density ...

a-method-to-estimate-cadaveric-femur-cortical-strains-during-fracture

A Method to Estimate Cadaveric Femur Cortical Strains During Fracture Testing Using Digital Image Correlation

This protocol describes the method using digital image correlation to estimate cortical strain from high speed video images of the cadaveric femoral ...

Mayo Clinic

Clinical implementation of quantitative computed tomography-based finite element analysis (QCT/FEA) of proximal femur stiffness and strength to assess the likelihood of proximal femur (hip) fractures requires a unified modeling procedure, consistency in predicting bone mechanical properties, and validation with realistic test data that represent typical hip fractures, specifically, a sideways fall on the hip. We, therefore, used two sets (nÂ =Â 9, each) of cadaveric femora with bone densities varying from normal to osteoporotic to build, refine, and validate a new class of QCT/FEA models for hip fracture under loading conditions that simulate a sideways fall on the hip. Convergence requirements of finite element models of the first set of femora led to the creation of a new meshing strategy and a robust process to model proximal femur geometry and material properties from QCT images. We used a second set of femora to cross-validate the model parameters derived from the first set. Refined models were validated experimentally by fracturing femora using specially designed fixtures, load cells, and high speed video capture. CT image reconstructions of fractured femora were created to classify the fractures. The predicted stiffness (cross-validation R (2)Â =Â 0.87), fracture load (cross-validation R (2)Â =Â 0.85), and fracture patterns (83% agreement) correlated well with experimental data.

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

Application clinique des quantitative calcul&eacute;e analyse ax&eacute;e sur la tomographie par &eacute;l&eacute;ments finis (QCT/FEA) du f&eacute;mur proximal rigidit&eacute; et r&eacute;sistance d&#39;&eacute;valuer le risque de fractures du f&eacute;mur proximal de la (hanche) n&eacute;cessite une proc&eacute;dure unified modeling, coh&eacute;rence dans la pr&eacute;diction des propri&eacute;t&eacute;s m&eacute;caniques osseuses, et validation avec test r&eacute;alistes donn&eacute;es qui repr&eacute;sentent des fractures de la hanche typiques, plus pr&eacute;cis&eacute;ment, un c&ocirc;t&eacute; tombent sur la hanche. Nous avons, par cons&eacute;quent, utilis&eacute; deux ensembles (n = 9, chaque) de f&eacute;murs cadav&eacute;riques avec densit&eacute; osseuse variant de normal &agrave; ost&eacute;oporotique &agrave; construire, affiner et valider une nouvelle classe de mod&egrave;les QCT/FEA pour fracture de la hanche sous chargement des conditions qui simulent une chute sur le c&ocirc;t&eacute; sur la hanche. Exigences en mati&egrave;re de convergence des mod&egrave;les d&#39;&eacute;l&eacute;ments finis de la premi&egrave;re s&eacute;rie de f&eacute;murs a conduit &agrave; la cr&eacute;ation d&#39;une nouvelle strat&eacute;gie de maillage et d&#39;un processus rigoureux aux propri&eacute;t&eacute;s de la g&eacute;om&eacute;trie et les mat&eacute;riaux du f&eacute;mur proximal mod&egrave;le d&#39;images QCT. Nous avons utilis&eacute; une seconde s&eacute;rie de f&eacute;murs pour effectuer une validation crois&eacute;e des param&egrave;tres du mod&egrave;le d&eacute;riv&eacute;s de la premi&egrave;re s&eacute;rie. Les mod&egrave;les raffin&eacute;s ont &eacute;t&eacute; valid&eacute;es exp&eacute;rimentalement par fracturation f&eacute;murs en utilisant des appareils sp&eacute;cialement con&ccedil;us, pesons et capture vid&eacute;o haute vitesse. Reconstitutions image CT des f&eacute;murs fractur&eacute;s ont &eacute;t&eacute; cr&eacute;&eacute;es pour classer les fractures. La rigidit&eacute; pr&eacute;dite (validation crois&eacute;e R (2) = 0,87), charge de rupture (validation crois&eacute;e R (2) = 0,85) et les patrons (83 % d&#39;accord) en corr&eacute;lation avec les donn&eacute;es exp&eacute;rimentales de fracture.

Des mod&egrave;les robustes de QCT/FEA de la rigidit&eacute; du f&eacute;mur proximal et fracture chargement lors d&#39;une chute sur le c&ocirc;t&eacute; sur la hanche.

Implementazione clinica di quantitativi calcolati analisi agli elementi finiti basati su tomografia computerizzata (QCT/FEA) di resistenza e solidit&agrave; per valutare la probabilit&agrave; di (anca) fratture del femore prossimale del femore prossimale richiede una procedura di modellazione unificato, coerenza nel predire le propriet&agrave; meccaniche di osso, e la convalida con dati di prova realistici che rappresentano le tipiche fratture dell&#39;anca, in particolare, una laterali caduta sull&#39;anca. Abbiamo, quindi, utilizzato due set (n = 9, ciascuna) di cadaverico femori con densit&agrave; ossea varia da normale a osteoporotici a costruire, affinare e convalidare una nuova classe di modelli QCT/FEA per frattura dell&#39;anca sotto condizioni che simulano una caduta lateralmente sul fianco di carico. Requisiti di convergenza dei modelli agli elementi finiti del primo set dei femori ha portato alla creazione di una nuova strategia di ingranamento e un robusto processo di propriet&agrave; geometria e materiale del femore prossimale modello da immagini QCT. Abbiamo utilizzato un secondo set di femori per la convalida incrociata i parametri del modello derivati dal primo set. Modelli raffinati sono stati convalidati sperimentalmente da fratturazione femori utilizzando apparecchi appositamente progettati, celle di carico e cattura di video ad alta velocit&agrave;. Ricostruzioni di immagini CT del femore fratturate sono stati creati per classificare le fratture. Il predetta rigidit&agrave; (cross-validazione R (2) = 0.87), carico di rottura (cross-validazione R (2) = 0,85) e frattura modelli (83% accordo) correlati anche con dati sperimentali.

ArticleTotal : 3	Year
Publication title Cited by 9	2017
Publication title Cited by 3	2017
Publication title Cited by 4	2017

Sean McEligot

Biography

JoVE Journal Publications

Other Publications