Numerical investigations on the biomechanical compatibility of hip-joint endoprostheses

Lutz, André; Nackenhorst, Udo

doi:10.1007/s00419-009-0380-4

Cited by 11 publications

(3 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For each of the 16 femora, the macro-geometry of the mFE model was obtained from the quantitative µCT, and meshed with tetrahedral elements (~ 115,000) with mean edge size of 0.17 mm (Lutz and Nackenhorst, 2010). An element was considered bone, not marrow, if its calcium hydroxyapatite density was at least 0.5 g/cm 3 .…”

Section: Methodsmentioning

confidence: 99%

“…The algorithm chooses randomly among such percentages with the restriction of a smaller than 10° change between orientations in adjacent elements (Ascenzi and Lomovtsev, 2006; Ascenzi et al, 2008). We also prepared 16 so-called density-only models with element-specific elastic isotropic properties computed from µCT vTMD (Lutz and Nackenhorst, 2010). We computed the Young’s modulus

normalE = E_{o} {false(normalρ / ρ_{o} false)}^{2}

with E o = 6250 MPa, ρ o =2 g/cm 3 , ρ as vTMD.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Hyperlipidemia affects multiscale structure and strength of murine femur

Ascenzi

Lutz

et al. 2014

Journal of Biomechanics

View full text Add to dashboard Cite

To improve bone strength prediction beyond limitations of assessment founded solely on the bone mineral component, we investigated the effect of hyperlipidemia, present in more than 40% of osteoporotic patients, on multiscale structure of murine bone. Our overarching purpose is to estimate bone strength accurately, to facilitate mitigating fracture morbidity and mortality in patients. Because i) orientation of collagen type I affects, independently of degree of mineralization, cortical bone’s micro-structural strength; and, ii) hyperlipidemia affects collagen orientation and µCT volumetric tissue mineral density (vTMD) in murine cortical bone, we have constructed the first multiscale finite element (mFE), mouse-specific femoral model to study the effect of collagen orientation and vTMD on strength in Ldlr−/−, a mouse model of hyperlipidemia, and its control wild type, on either high fat diet or normal diet. Each µCT scan-based mFE model included either element-specific elastic orthotropic properties calculated from collagen orientation and vTMD (collagen-density model) by experimentally validated formulation, or usual element-specific elastic isotropic material properties dependent on vTMD-only (density-only model). We found that collagen orientation, assessed by circularly polarized light and confocal microscopies, and vTMD, differed among groups; and that microindentation results strongly correlate with elastic modulus of collagen-density models (r2=0.85, p=10−5). Collagen-density models yielded 1) larger strains, and therefore lower strength, in simulations of 3-point bending and physiological loading; and 2) higher correlation between mFE-predicted strength and 3-point bending experimental strength, than density-only models. This novel method supports ongoing translational research to achieve the as yet elusive goal of accurate bone strength prediction.

show abstract

Section: Methodsmentioning

confidence: 99%

normalE = E_{o} {false(normalρ / ρ_{o} false)}^{2}

with E o = 6250 MPa, ρ o =2 g/cm 3 , ρ as vTMD.…”

Section: Methodsmentioning

confidence: 99%

Hyperlipidemia affects multiscale structure and strength of murine femur

Ascenzi

Lutz

et al. 2014

Journal of Biomechanics

View full text Add to dashboard Cite

show abstract

“…For a more detailed description concerning the modeling approach, it is referred to Lutz and Nackenhorst (2009). According to the constitutive law, the elastic modulus of bone ranges between E b = 0 .…”

Section: Finite Element Modelingmentioning

confidence: 99%

Numerical studies on alternative therapies for femoral head necrosis

Lutz

Nackenhorst

Lewinski

et al. 2010

Biomech Model Mechanobiol

Self Cite

View full text Add to dashboard Cite

Numerical investigations with regard to the subtrochanteric fracture risk induced by three alternative methods for the treatment of femoral head necrosis are outlined in this presentation. The traditional core decompression technique will be compared with minimal invasive multiple low diameter drillings and the implantation of an innovative tantalum implant. With emphasis to the newly introduced computational strategies and modeling approaches, the modeling of critical loading conditions as well as mesh convergence is outlined in detail. In addition to the immediate postoperative fracture risk, the long-term stability of the different approaches for treating femoral head necrosis is predicted by performing well-established bone remodeling simulation techniques. The computed results are augmented for results obtained from clinical experience.

show abstract

How to Push Computational Bio-Mechanics to Clinical Application?

Nackenhorst

Bittens

2022

Current Trends and Open Problems in Computational Mechanics

View full text Add to dashboard Cite

Numerical investigations on the biomechanical compatibility of hip-joint endoprostheses

Cited by 11 publications

References 42 publications

Hyperlipidemia affects multiscale structure and strength of murine femur

Hyperlipidemia affects multiscale structure and strength of murine femur

Numerical studies on alternative therapies for femoral head necrosis

How to Push Computational Bio-Mechanics to Clinical Application?

Contact Info

Product

Resources

About