The Effect of Ultrasonically Determined Anisotropy on Longitudinal Fracture of Cortical Bone

Abstract

This study examines the effects of density and microstructural anisotropy on longitudinal crack propagation in compact bone. Bovine cortical bone samples were demineralized by acid, producing specimens with a wide range of bone density. Ultrasound velocity was measured in the radial and longitudinal directions of each specimen using a pulse transmission technique. A proposed microstructural anisotropy parameter based on these ultrasound velocities was introduced and evaluated. The critical stress intensity factors K_IC of these specimens were determined by mechanical fracture toughness tests. A linear regression study demonstrated that assessment of fracture toughness was precisely achieved by the combined effect of density and microstructural anisotropy of compact bone (r² = 0.951, p < 0.0001).

Keywords

fracture toughness anisotropy ultrasound density cortical bone

Get full access to this article

View all access options for this article.

References

Bonfield

W. J.

Advances in the fracture mechanics of cortical bone. J. Biomechanics, 1987, 20, 1071–1081.

Evans

F. G.

Mechanical properties of bone, 1973 (Thomas, Springfield, Illinois).

Carter

D. R.

Hayes

W. C.

Bone compressive strength: The influence of density and strain rate. Science, 1976, 194, 1174–1176.

Hayes

W. C.

Gerhart

T. N.

Biomechanics of bone: Applications for assessment of bone strength. In Bone and mineral research ( Peck

W. A.

), 1985, pp. 259–294 (Elsevier Science).

Wall

J. C.

Chatterji

S. K.

Jeffery

J. W.

Age-related changes in the density and tensile strength of human femoral cortical bone. Calcif. Tissue Int., 1979, 27, 105–108.

Melvin

J. W.

Fracture mechanics of bone. J. Biomechanical Engng, 1993, 115, 549–554.

Behiri

J. C.

Bonfield

W. J.

Fracture mechanics of bone—the effects of density, specimen thickness and crack velocity on longitudinal fracture. J. Biomechanics, 1984, 17, 25–34.

Norman

T. L.

Vashishth

Burr

D. B.

Fracture toughness of human bone under tension. J. Biomechanics, 1995, 28, 309–320.

Ashman

R. B.

Rho

J. Y.

Turner

C. H.

Anatomical variation of orthotropic elastic moduli of the proximal human tibia. J. Biomechanics, 1989, 22, 1–6.

10.

Ashman

R. B.

Corin

J. D.

Turner

C. H.

Elastic properties of cancellous bone: Measurement by an ultrasonic technique. J. Biomechanics, 1987, 20, 979–986.

11.

Zagzebski

J. A.

Rossman

P. J.

Mesina

Mazess

R. B.

Madsen

E. L.

Ultrasound transmission measurements through the os calcis. Calcif. Tissue Int., 1991, 49, 107–111.

12.

Massie

Reid

Porter

Screening for osteoporosis: Comparison between dual energy x-ray absorptiometry and BUA in 1000 premenopausal women. Osteoporosis Int., 1992, 3, 107–110.

13.

Turner

C. H.

Eich

Ultrasonic velocity as a predictor of strength in bovine cancellous bone. Calcif. Tissue Int., 1991, 49, 116–119.

14.

Schott

A. M.

Hans

Sornay-Rendu

Delmas

P. D.

Meunier

P. J.

Ultrasound measurements on os calcis: Precision and age-related changes in a normal female population. Osteoporosis Int., 1993, 3, 249–254.

15.

Ashman

R. B.

Cowin

S. C.

Van Buskirk

W. C.

Rice

J. C.

A continuous wave technique for the measurement of the elastic properties of cortical bone. J. Biomechanics, 1984, 17, 349–361.

16.

Behiri

J. C.

Bonfield

W. J.

Crack velocity dependence of longitudinal fracture in bone. J. Mater. Sci., 1980, 15, 1841–1849.

17.

Boyce

T. M.

Bloebaum

R. D.

Cortical aging differences and fracture implications for the human femoral neck. Bone, 1993, 14, 769–778.

18.

Fine

M. E.

Ritchie

R. O.

Fatigue-crack initiation and near threshold crack growth, fatigue and microstructure, 1978 (American Society for Metals, Metals Park, Ohio).

19.

Askeland

D. R.

The science and engineering of materials, 2nd edition, 1989 (PWS-KENT).