Journal ArticleDOI
Development of an Inertia-Driven Model of Sideways Fall for Detailed Study of Femur Fracture Mechanics
TLDR
These tools will allow more biofidelic laboratory simulation of falls to the side, and more detailed analysis of proximal femur failure mechanisms using human cadaver specimens.Abstract:
A new method for laboratory testing of human proximal femora in conditions simulating a sideways fall was developed. Additionally, in order to analyze the strain state in future cadaveric tests, digital image correlation (DIC) was validated as a tool for strain field measurement on the bone of the femoral neck. A fall simulator which included models for the body mass, combined lateral femur and pelvis mass, pelvis stiffness, and trochanteric soft tissue was designed. The characteristics of each element were derived and developed based on human data from the literature. The simulator was verified by loading a state-of-the-art surrogate femur and comparing the resulting force-time trace to published, human volunteer experiments. To validate the DIC, 20 human proximal femora were prepared with a strain rosette and speckle paint pattern, and loaded to 50% of their predicted failure load at a low compression rate. Strain rosettes were taken as the gold standard, and minimum principal strains from the DIC and the rosettes were compared using descriptive statistics. The initial slope of the force-time curve obtained in the fall simulator matched published human volunteer data, with local peaks superimposed in the model due to internal vibrations of the spring used to model the pelvis stiffness. Global force magnitude and temporal characteristics were within 2% of published volunteer experiments. The DIC minimum principal strains were found to be accurate to 127±239 μɛ. These tools will allow more biofidelic laboratory simulation of falls to the side, and more detailed analysis of proximal femur failure mechanisms using human cadaver specimens.read more
Citations
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Journal ArticleDOI
Fully porous 3D printed titanium femoral stem to reduce stress-shielding following total hip arthroplasty
TL;DR: It is shown that the fully porous implant with an optimized material micro‐structure can reduce the amount of bone loss secondary to stress shielding by 75% compared to a fully solid implant.
Journal ArticleDOI
The use of digital image correlation in the biomechanical area: a review
TL;DR: In this article, the potentialities and limitations of digital image correlation (DIC) as a technique for measuring displacements and strain in biomechanical applications are summarized and compared, whilst open issues are addressed.
Journal ArticleDOI
Extracting accurate strain measurements in bone mechanics: A critical review of current methods.
Lorenzo Grassi,Hanna Isaksson +1 more
TL;DR: This review of literature examined the four most commonly adopted methods for strain measurements (strain gauges, fibre Bragg grating sensors, digital image correlation, and digital volume correlation), with a focus on studies with bone as a substrate material, at the organ and tissue level.
Journal ArticleDOI
How accurately can subject-specific finite element models predict strains and strength of human femora? Investigation using full-field measurements
TL;DR: Despite the low sample size and the single loading condition tested, the present combined numerical-experimental method showed that finite element models can predict femoral strength by providing a thorough description of the local bone mechanical response.
Journal ArticleDOI
Strain distribution in the proximal Human femur during in vitro simulated sideways fall
TL;DR: Principal strains during a sideways fall were nearly perpendicular to the direction of principal strains for physiological loading, associated with a specific fracture mechanism during sideways fall, where failure initiated on the superior-lateral side (compression) followed by later failure of the medially (tension).
References
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Journal ArticleDOI
Changes in Trabecular Pattern of the Upper End of the Femur as an Index of Osteoporosis
TL;DR: Roentgenograms of the hip region, in a series of thirty-five patients above the age of fifty years, were studied with particular reference to the trabecular pattern of the upper end of the femur, suggesting that these patterns can be utilized as a roentgenographic scale for the diagnosis and grading of osteoporosis.
Journal ArticleDOI
Comparison of the elastic and yield properties of human femoral trabecular and cortical bone tissue.
Harun H. Bayraktar,Elise F. Morgan,Glen L. Niebur,Grayson Morris,Eric K. Wong,Tony M. Keaveny +5 more
TL;DR: While the elastic modulus and yield strains for trabecular tissue are just slightly lower than those of cortical tissue, because of the cumulative effect of these differences, tissue strength is about 25% greater for cortical bone.
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BMD at Multiple Sites and Risk of Fracture of Multiple Types: Long-Term Results From the Study of Osteoporotic Fractures
Katie L. Stone,Dana G. Seeley,Li Yung Lui,Jane A. Cauley,Kristine E. Ensrud,Warren S. Browner,Michael C. Nevitt,Steven R. Cummings +7 more
TL;DR: Almost all fracture types to be related to low BMD are found, and the overall proportion of fractures attributable toLow BMD is modest.
Journal ArticleDOI
Bone mineral density thresholds for pharmacological intervention to prevent fractures
Ethel S. Siris,Y. T. Chen,Thomas A. Abbott,Elizabeth Barrett-Connor,Paul D. Miller,Lois E. Wehren,Marc L. Berger +6 more
TL;DR: A strategy to reduce overall fracture incidence will likely require lifestyle changes and a targeted effort to identify and develop treatment protocols for women with less severe low bone mass who are nonetheless at increased risk for future fractures.
Journal ArticleDOI
Estimating hip fracture morbidity, mortality and costs.
TL;DR: To estimate lifetime morbidity, mortality, and costs from hip fracture incorporating the effect of deficits in activities of daily living, a large number of patients with hip fracture have had at least one hip replacement.