Impact-induced fissuring of articular cartilage:

An investigation of failure criteria.

J. Biomechanical Engineering. 120(2):181-187, 1998.

Atkinson, TS, Haut, RC, Altiero, NJ.

Abstract:

Cartilage consists of both solid and fluid phases which interact to support loads. Fissures observed on the surface of articular cartilage occur in the solid portion. In order to determine which of the solid phase stresses provides the best predictor for the initiation of a fissure, elastic stresses from a series of in vitro impact experiments were used to derive stresses in the solid phase of the cartilage. This stress information was then analyzed using a logistic regression in order to identify the best predictor of fissuring. The mechanical analysis indicated that low magnitude tensile solid hoop stress develops in the solid phase and acts around the hemispherical contact zone in impacts involving the two smaller radius interfaces. The logistic regression, however, indicated that maximum principal solid stress was not a predictor for the occurrence of a fissure. Maximum shear stress in the solid (which is equivalent to shear stress from the elastic analysis) was the best predictor of the occurrence of a fissure. This study helps support the suggestion that in stress fields dominated by compression, the maximum shear stress from the elastic analysis may be used to predict fissure initiation in cartilage.

Orthopaedic Biomechanics Laboratories,

College of Osteopathic Medicine,

Michigan State University,

East Lansing, Michigan 48824

Please address correspondence to:

Roger C. Haut, Ph.D.,

Orthopaedic Biomechanics Laboratory,

College of Osteopathic Medicine,

A414 East Fee Hall,

Michigan State University,

East Lansing, MI 48824,

Tel: (517)355-0320,

Fax: (517)353-0789,

E-mail: haut@msu.edu