Geometric properties of equine metacarpi

Piotrowski, George; Sullivan, Mark; Colahan, Patrick T.

doi:10.1016/0021-9290(83)90036-2

Cited by 33 publications

(51 citation statements)

References 5 publications

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“…Piotrowski et al (1983) have shown that splint bones have important influences on inertial properties such as the second moment of area (and hence bending rigidity) in the proximal one-third diaphysis. Near mid-diaphysis, however, splint bones of younger horses (<2 years old) typically are not fused to the MC3 , and therefore have minimal influence on bending rigidity (Piotrowski et al, 1983). Splint-bone fusion, which is more common in animals >2 years , may enhance local loading-carrying capacity (e.g.…”

Section: Discussionmentioning

confidence: 99%

“…Splint-bone fusion, which is more common in animals >2 years , may enhance local loading-carrying capacity (e.g. on the order of 10-15% increased bending rigidity in the craniocaudal axis) (Piotrowski et al, 1983;Nunamaker, 2001). These facts demonstrate that cortical thickness, which can be enhanced in the caudal cortices by splint-bone fusion, may help resist deleterious loading conditions.…”

Section: Discussionmentioning

confidence: 99%

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Are uniform regional safety factors an objective of adaptive modeling/remodeling in cortical bone?

Skedros¹,

Dayton²,

Sybrowsky³

et al. 2003

Journal of Experimental Biology

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Mechanical strains produced by functional loading influence the cellular activities responsible for normal appendicular bone development and maintenance. Contemporary investigations recognize that modeling and remodeling processes mediate the strain-related structural and material adaptations produced during normal bone development. However, the goals towards which such adaptations are directed remain unclear. hypothesized that a possible objective for regional variations in material organization between cortical locations of a limb bone diaphysis may be the maintenance of uniform stresses throughout a bone's crosssection. Examining mature ovine radii at mid-diaphysis, they found that the narrower caudal 'compression' cortex had a lower elastic modulus than the thicker, less-highly strained cranial (dorsal) 'tension' cortex. Riggs et al. (1993) reported similar elastic modulus differences between the cranial 'tension' and caudal 'compression' cortices of the equine radius at mid-diaphysis, even though these regions have nearly equivalent cortical thickness. These elastic modulus differences were attributed to significant regional variations between the cranial and caudal cortices, including more oblique-to-transverse collagen fiber orientation, lower mineral content, and increased remodeling with secondary osteons in the caudal cortex. These authors suggested that since cranial versus caudal stresses are significantly different in each species, and the associated remodeling responses appeared to amplify this difference, the non-uniform stress distribution represents a goal of developmental adaptation. Because yield and ultimate stress of cortical bone are lower in tension than in compression (Reilly and Burstein, 1975), and the nonuniform stress distributions of ovine and equine radii resulted in roughly equivalent safety factors between the cranial and caudal cortices, the achievement of equivalent or uniform 'regional' safety factors (e.g. cranial cortex = caudal cortex) was offered as an explanation for a major goal of adaptation in these bones Riggs et al., 1993).Safety factors, when considered in skeletal biomechanics, usually refer to an entire bone (Rubin and Lanyon, 1982;Biewener, 1993). In the present study we further examine the idea of 'regional' safety factors; for example, those from a distinct cortical location within the same transverse crosssection Riggs et al., 1993). In either case, It has been hypothesized that a major objective of morphological adaptation in limb-bone diaphyses is the achievement of uniform regional safety factors between discrete cortical locations (e.g. between cranial and caudal cortices at mid-diaphysis). This hypothesis has been tested, and appears to be supported in the diaphyses of ovine and equine radii. The present study more rigorously examined this question using the equine third metacarpal (MC3), which has had functionally generated intracortical strains estimated by a sophisticated finite element model. Mechanical properties of multiple mid-diaphyseal specimens ...

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Are uniform regional safety factors an objective of adaptive modeling/remodeling in cortical bone?

Skedros¹,

Dayton²,

Sybrowsky³

et al. 2003

Journal of Experimental Biology

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“…2.5 times the body weight, whereas during trotting the loading can be up to 5 times the body weight. The ultimate compression stress during trotting is around 45 MPa, but fracture strength is beyond 85 MPa (Piotrowski 1983).…”

Section: Introductionmentioning

confidence: 99%

Bending and torsional stiffness measurements of equine radii and tibiae

Suéry

Piskoty

Schmidlin

et al. 2014

PHK

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Summary: This study was a re-evaluation of static mechanical testing of equine long bones as part of a larger study on impact failure modes and strength of the same bones. Supplementary to other morphological and mechanical tests, static stiffness properties of these long bones were non-destructively determined. The goal was to quantify stiffness properties of the diaphysis of equine radii and tibiae in quasi-static bending as well as when loaded in torsion and to check for possible age and gender effects on these properties. Fifty-six equine bones (tibiae and radii) from fifteen horses were first tested in a torsion machine and subsequently fifty-five of them investigated using a 3-point-bending test-setup. A maximum torque of 150 N*m and a maximum bending moment of 920 N*m were applied in steps. Loading and unloading was performed in order to check for hysteresis effects. The outcome for both type of bones (tibiae and radii) was described statistically in relation to age (young, middle aged, and old) and gender (geldings and mares). Additional information on the side (left and right), breed and use of the horse (competition versus 'other', such as pleasure) was excluded from statistical modelling after preliminary analysis. While the loading-unloading cycles in bending showed some hysteresis due to localized deformation, the unloading curve followed the loading curve in torsional loading. Bending stiffness of tibiae is on average 6'813 N/mm and of radii 6'130 N/mm. Torsional stiffness of tibiae is 2.36*10 6 N*m(rad/mm), and of radii 1.90*10 6 N*m(rad/mm). Tibiae were clearly stiffer than radii. A trend of higher bone stiffness for geldings compared with mares and for younger horses could be found, although not statistically significant.Keywords: bones / horses / bending / torsion / stiffness / orthopedics Citation: Michel S., Piskoty G., Schmidlin A., Fürst A. (2014) Bending and torsional stiffness measurements of equine radii and tibiae. Pferdeheilkunde 30, 577-584Correspondence: Silvain Michel, Dipl. Ing. ETH, Mechanical Systems Engineering, Empa -Materials Science and Technology, Überland-strasse 129, 8600 Dübendorf, Switzerland, E-mail: silvain.michel@empa.chBending and torsional stiffness measurements of equine radii and tibiae S. Michel et al.

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“…Nos McIIIs com PM, o aumento do CD foi mais acentuado especialmente a partir da quarta avaliação no lado direito e da sexta avaliação no esquerdo. O aumento de espessura do CD, nos potros com PM, corrobora os achados de NUNAMAKER & PROVOST (1991) e caracteriza a resposta do CD à carga excessiva de treinamento (PIOTROWSKI et al, 1983;EVANS et al, 1992;McCARTHY & JEFFCOTT, 1992 A tabela 4 mostra que houve diferença (P<0,05) somente entre machos e fêmeas no aumento de espessura do CDD e do CDE. O aumento médio de espessura do CDD e do CDE foi de 23,2mm e 22,0mm, respectivamente, nas fêmeas, e de 7,6mm e 7,1mm, respectivamente, nos machos.…”

Section: Resultsunclassified