Osteonal effects on elastic modulus and fatigue life in equine bone

V. A. Gibson, Susan M Stover, J. C. Gibeling, S. J. Hazelwood, R. B. Martin

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

We hypothesized that recently formed, incompletely mineralized, and thus, relatively deformable osteons in the equine third metacarpus enhance in vitro load-controlled fatigue life in two ways. Macroscopically, there is a compliance effect, because reduced tissue elastic modulus diminishes the stress required to reach a given strain. Microscopically, there is a cement line effect, in which new osteons and their cement lines more effectively serve as barriers to crack propagation. We studied 18 4×10×100 mm beams from the medial, lateral, and dorsal cortices of metacarpal bones from 6 thoroughbred racehorses. Following load-controlled fatigue testing to fracture in 4 point bending, a transverse, 100 μm thick, basic fuchsin-stained cross-section was taken from the load-bearing region. The number and diameter of all intact (and thus recently formed/compliant) secondary osteons in a 3.8×3.8 mm region in the center of the section were determined. The associated area fraction and cement line length of intact osteons were calculated, and the relationships between these variables, elastic modulus (E), and the logarithm of fatigue life (log NF) were analyzed. As expected, log NF was negatively correlated with E, which was in turn negatively correlated with intact osteon area fraction and density. (Log NF)/E increased in proportion to intact osteon density and nonlinearly with cement line density (mm/mm 2). These results support the hypothesis that remodeling extends load-controlled fatigue life both through the creation of osteonal barriers to microdamage propagation and modulus reduction.

Original languageEnglish (US)
Pages (from-to)217-225
Number of pages9
JournalJournal of Biomechanics
Volume39
Issue number2
DOIs
StatePublished - 2006

Fingerprint

Haversian System
Elastic Modulus
Horses
Fatigue
Bone
Cements
Elastic moduli
Fatigue of materials
Bone and Bones
Bearings (structural)
Fatigue testing
Metacarpus
Crack propagation
Metacarpal Bones
Weight-Bearing
Tissue
Compliance

Keywords

  • Bone
  • Cement line
  • Elastic modulus
  • Equine
  • Fatigue life
  • Osteon
  • Remodeling

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

Cite this

Osteonal effects on elastic modulus and fatigue life in equine bone. / Gibson, V. A.; Stover, Susan M; Gibeling, J. C.; Hazelwood, S. J.; Martin, R. B.

In: Journal of Biomechanics, Vol. 39, No. 2, 2006, p. 217-225.

Research output: Contribution to journalArticle

Gibson, V. A. ; Stover, Susan M ; Gibeling, J. C. ; Hazelwood, S. J. ; Martin, R. B. / Osteonal effects on elastic modulus and fatigue life in equine bone. In: Journal of Biomechanics. 2006 ; Vol. 39, No. 2. pp. 217-225.
@article{32a44690a3534557a9848bb4d7a8593b,
title = "Osteonal effects on elastic modulus and fatigue life in equine bone",
abstract = "We hypothesized that recently formed, incompletely mineralized, and thus, relatively deformable osteons in the equine third metacarpus enhance in vitro load-controlled fatigue life in two ways. Macroscopically, there is a compliance effect, because reduced tissue elastic modulus diminishes the stress required to reach a given strain. Microscopically, there is a cement line effect, in which new osteons and their cement lines more effectively serve as barriers to crack propagation. We studied 18 4×10×100 mm beams from the medial, lateral, and dorsal cortices of metacarpal bones from 6 thoroughbred racehorses. Following load-controlled fatigue testing to fracture in 4 point bending, a transverse, 100 μm thick, basic fuchsin-stained cross-section was taken from the load-bearing region. The number and diameter of all intact (and thus recently formed/compliant) secondary osteons in a 3.8×3.8 mm region in the center of the section were determined. The associated area fraction and cement line length of intact osteons were calculated, and the relationships between these variables, elastic modulus (E), and the logarithm of fatigue life (log NF) were analyzed. As expected, log NF was negatively correlated with E, which was in turn negatively correlated with intact osteon area fraction and density. (Log NF)/E increased in proportion to intact osteon density and nonlinearly with cement line density (mm/mm 2). These results support the hypothesis that remodeling extends load-controlled fatigue life both through the creation of osteonal barriers to microdamage propagation and modulus reduction.",
keywords = "Bone, Cement line, Elastic modulus, Equine, Fatigue life, Osteon, Remodeling",
author = "Gibson, {V. A.} and Stover, {Susan M} and Gibeling, {J. C.} and Hazelwood, {S. J.} and Martin, {R. B.}",
year = "2006",
doi = "10.1016/j.jbiomech.2004.12.002",
language = "English (US)",
volume = "39",
pages = "217--225",
journal = "Journal of Biomechanics",
issn = "0021-9290",
publisher = "Elsevier Limited",
number = "2",

}

TY - JOUR

T1 - Osteonal effects on elastic modulus and fatigue life in equine bone

AU - Gibson, V. A.

AU - Stover, Susan M

AU - Gibeling, J. C.

AU - Hazelwood, S. J.

AU - Martin, R. B.

PY - 2006

Y1 - 2006

N2 - We hypothesized that recently formed, incompletely mineralized, and thus, relatively deformable osteons in the equine third metacarpus enhance in vitro load-controlled fatigue life in two ways. Macroscopically, there is a compliance effect, because reduced tissue elastic modulus diminishes the stress required to reach a given strain. Microscopically, there is a cement line effect, in which new osteons and their cement lines more effectively serve as barriers to crack propagation. We studied 18 4×10×100 mm beams from the medial, lateral, and dorsal cortices of metacarpal bones from 6 thoroughbred racehorses. Following load-controlled fatigue testing to fracture in 4 point bending, a transverse, 100 μm thick, basic fuchsin-stained cross-section was taken from the load-bearing region. The number and diameter of all intact (and thus recently formed/compliant) secondary osteons in a 3.8×3.8 mm region in the center of the section were determined. The associated area fraction and cement line length of intact osteons were calculated, and the relationships between these variables, elastic modulus (E), and the logarithm of fatigue life (log NF) were analyzed. As expected, log NF was negatively correlated with E, which was in turn negatively correlated with intact osteon area fraction and density. (Log NF)/E increased in proportion to intact osteon density and nonlinearly with cement line density (mm/mm 2). These results support the hypothesis that remodeling extends load-controlled fatigue life both through the creation of osteonal barriers to microdamage propagation and modulus reduction.

AB - We hypothesized that recently formed, incompletely mineralized, and thus, relatively deformable osteons in the equine third metacarpus enhance in vitro load-controlled fatigue life in two ways. Macroscopically, there is a compliance effect, because reduced tissue elastic modulus diminishes the stress required to reach a given strain. Microscopically, there is a cement line effect, in which new osteons and their cement lines more effectively serve as barriers to crack propagation. We studied 18 4×10×100 mm beams from the medial, lateral, and dorsal cortices of metacarpal bones from 6 thoroughbred racehorses. Following load-controlled fatigue testing to fracture in 4 point bending, a transverse, 100 μm thick, basic fuchsin-stained cross-section was taken from the load-bearing region. The number and diameter of all intact (and thus recently formed/compliant) secondary osteons in a 3.8×3.8 mm region in the center of the section were determined. The associated area fraction and cement line length of intact osteons were calculated, and the relationships between these variables, elastic modulus (E), and the logarithm of fatigue life (log NF) were analyzed. As expected, log NF was negatively correlated with E, which was in turn negatively correlated with intact osteon area fraction and density. (Log NF)/E increased in proportion to intact osteon density and nonlinearly with cement line density (mm/mm 2). These results support the hypothesis that remodeling extends load-controlled fatigue life both through the creation of osteonal barriers to microdamage propagation and modulus reduction.

KW - Bone

KW - Cement line

KW - Elastic modulus

KW - Equine

KW - Fatigue life

KW - Osteon

KW - Remodeling

UR - http://www.scopus.com/inward/record.url?scp=28444467406&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=28444467406&partnerID=8YFLogxK

U2 - 10.1016/j.jbiomech.2004.12.002

DO - 10.1016/j.jbiomech.2004.12.002

M3 - Article

C2 - 16321623

AN - SCOPUS:28444467406

VL - 39

SP - 217

EP - 225

JO - Journal of Biomechanics

JF - Journal of Biomechanics

SN - 0021-9290

IS - 2

ER -