Torsional strength reduction due to cortical defects in bone

B. C. Edgerton, K. N. An, B. F. Morrey

Research output: Contribution to journalArticle

105 Citations (Scopus)

Abstract

This study correlated torsional strength reduction with circular defect size in cortical bone, to define the ''stress riser'' and ''open-section'' effect of the defects. The experimental model was developed and verified. Circular defects from 10 to 60% of bone diameter were then created in paired sheep femora and the bones loaded to failure. Contrary to theory, this experimental study suggests that small defects (10%) of bone diameter cause no significant torsional strength reduction. A 20% defect caused a 34% decrease in strength, representing the ''stress riser'' dimension. Defects between 20 and 60% of bone diameter decreased strength linearly as a function of defect size, and thus no discrete ''open section'' dimension was identified. For circular defects, we were unable to demonstrate a discrete ''open-section'' effect at which dramatic strength reduction is observed. These data may prove to be helpful when planning surgery that involves placing defects in bone such as for infection, biopsy, and prosthesis removal. The accepted guideline to avoid defects of greater than 50% of the bone diameter may be too great. Our data reveal this 62% reduction in torque strength and 88% energy to failure exist with a 50% circular defect.

Original languageEnglish (US)
Pages (from-to)851-855
Number of pages5
JournalJournal of Orthopaedic Research
Volume8
Issue number6
StatePublished - Nov 1990

Fingerprint

Bone and Bones
Torque
Femur
Prostheses and Implants
Sheep
Theoretical Models
Guidelines
Biopsy
Infection

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

Cite this

Edgerton, B. C., An, K. N., & Morrey, B. F. (1990). Torsional strength reduction due to cortical defects in bone. Journal of Orthopaedic Research, 8(6), 851-855.

Torsional strength reduction due to cortical defects in bone. / Edgerton, B. C.; An, K. N.; Morrey, B. F.

In: Journal of Orthopaedic Research, Vol. 8, No. 6, 11.1990, p. 851-855.

Research output: Contribution to journalArticle

Edgerton, BC, An, KN & Morrey, BF 1990, 'Torsional strength reduction due to cortical defects in bone', Journal of Orthopaedic Research, vol. 8, no. 6, pp. 851-855.
Edgerton, B. C. ; An, K. N. ; Morrey, B. F. / Torsional strength reduction due to cortical defects in bone. In: Journal of Orthopaedic Research. 1990 ; Vol. 8, No. 6. pp. 851-855.
@article{d2642d42a4344539beca8d50fb0b2f3f,
title = "Torsional strength reduction due to cortical defects in bone",
abstract = "This study correlated torsional strength reduction with circular defect size in cortical bone, to define the ''stress riser'' and ''open-section'' effect of the defects. The experimental model was developed and verified. Circular defects from 10 to 60{\%} of bone diameter were then created in paired sheep femora and the bones loaded to failure. Contrary to theory, this experimental study suggests that small defects (10{\%}) of bone diameter cause no significant torsional strength reduction. A 20{\%} defect caused a 34{\%} decrease in strength, representing the ''stress riser'' dimension. Defects between 20 and 60{\%} of bone diameter decreased strength linearly as a function of defect size, and thus no discrete ''open section'' dimension was identified. For circular defects, we were unable to demonstrate a discrete ''open-section'' effect at which dramatic strength reduction is observed. These data may prove to be helpful when planning surgery that involves placing defects in bone such as for infection, biopsy, and prosthesis removal. The accepted guideline to avoid defects of greater than 50{\%} of the bone diameter may be too great. Our data reveal this 62{\%} reduction in torque strength and 88{\%} energy to failure exist with a 50{\%} circular defect.",
author = "Edgerton, {B. C.} and An, {K. N.} and Morrey, {B. F.}",
year = "1990",
month = "11",
language = "English (US)",
volume = "8",
pages = "851--855",
journal = "Journal of Orthopaedic Research",
issn = "0736-0266",
publisher = "John Wiley and Sons Inc.",
number = "6",

}

TY - JOUR

T1 - Torsional strength reduction due to cortical defects in bone

AU - Edgerton, B. C.

AU - An, K. N.

AU - Morrey, B. F.

PY - 1990/11

Y1 - 1990/11

N2 - This study correlated torsional strength reduction with circular defect size in cortical bone, to define the ''stress riser'' and ''open-section'' effect of the defects. The experimental model was developed and verified. Circular defects from 10 to 60% of bone diameter were then created in paired sheep femora and the bones loaded to failure. Contrary to theory, this experimental study suggests that small defects (10%) of bone diameter cause no significant torsional strength reduction. A 20% defect caused a 34% decrease in strength, representing the ''stress riser'' dimension. Defects between 20 and 60% of bone diameter decreased strength linearly as a function of defect size, and thus no discrete ''open section'' dimension was identified. For circular defects, we were unable to demonstrate a discrete ''open-section'' effect at which dramatic strength reduction is observed. These data may prove to be helpful when planning surgery that involves placing defects in bone such as for infection, biopsy, and prosthesis removal. The accepted guideline to avoid defects of greater than 50% of the bone diameter may be too great. Our data reveal this 62% reduction in torque strength and 88% energy to failure exist with a 50% circular defect.

AB - This study correlated torsional strength reduction with circular defect size in cortical bone, to define the ''stress riser'' and ''open-section'' effect of the defects. The experimental model was developed and verified. Circular defects from 10 to 60% of bone diameter were then created in paired sheep femora and the bones loaded to failure. Contrary to theory, this experimental study suggests that small defects (10%) of bone diameter cause no significant torsional strength reduction. A 20% defect caused a 34% decrease in strength, representing the ''stress riser'' dimension. Defects between 20 and 60% of bone diameter decreased strength linearly as a function of defect size, and thus no discrete ''open section'' dimension was identified. For circular defects, we were unable to demonstrate a discrete ''open-section'' effect at which dramatic strength reduction is observed. These data may prove to be helpful when planning surgery that involves placing defects in bone such as for infection, biopsy, and prosthesis removal. The accepted guideline to avoid defects of greater than 50% of the bone diameter may be too great. Our data reveal this 62% reduction in torque strength and 88% energy to failure exist with a 50% circular defect.

UR - http://www.scopus.com/inward/record.url?scp=0025514223&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0025514223&partnerID=8YFLogxK

M3 - Article

VL - 8

SP - 851

EP - 855

JO - Journal of Orthopaedic Research

JF - Journal of Orthopaedic Research

SN - 0736-0266

IS - 6

ER -