C.P. Brown, A. Oloyede, H.R. Moody, and R.W. Crawford
Cartilage, arthroscopic indentation, osteoarthritis, surface
This paper outlines the motivation and preliminary
investigations into the possibility of a new method of
characterising cartilage health in vivo. Current in vivo
indentation techniques, which rely on stiffness
measurements alone, are unable to adequately distinguish
between healthy and degraded tissue. By considering the
tangential strain in the articular surface during an
indentation test, it is hypothesised that a simple and more
sensitive indicator of cartilage integrity may be possible.
The present study investigates the effects of low levels of
degradation on the tangential surface strain under the
indentor. Preliminary results suggest that this technique
is highly sensitive, and can discriminate between
degeneration and the natural variations across the joint.
From these investigations we propose that the relationship
between indentation and the surrounding strain field
might be able to distinguish between healthy soft tissue
and degraded tissue in vivo, important information not
available from the current techniques.
This study forms the basis of a series of further
experimental and modelling investigations to develop
these ideas with the goal of creating a more effective
diagnostic method for the surgeon.