Forma, Vol. 12 (Nos. 3, 4), pp. 225-233, 1997

The Relationship between Cancellous Bone Architecture and Mechanical Properties at a Continuum Level

C. H. Turner

Biomechanics and Biomaterials Research Center, IUPUI, CL 600, Indianapolis, IN 46202, U.S.A.

(Received February 23, 1996; Accepted November 11, 1996)

Keywords: Bone, Trabeculae, Fabric, Elasticity, Failure

Abstract. Cancellous bone is found near the joints and in the spine of vertebrates. It is a high-porosity, cellular material with struts, called trabeculae. The trabeculae typically are oriented producing an anisotropic structure that can be characterized by a measure called fabric. Fabric is best represented as a second rank tensor. Using tensor algebra, the elastic coefficients of cancellous bone have been presented as functions of fabric and porosity. Experimental studies have shown that the first best predictor of the elasticity and strength of cancellous bone is porosity (or density). The second best predictor is fabric. These studies have also suggested a simplified method, such as a maximum strain criterion, may be useful for predicting bone fracture. Accurate imaging techniques have been developed to measure bone density in patients and these measurements can be used to predict bone elasticity and strength. Clinical techniques are not yet available for the measurement of fabric in patients.