Cross sectional area measurement of tendon and ligament in vitro: a simple, rapid, non-destructive technique.

The structural properties of tendons and ligaments are integral to their ability to function effectively in vivo and are determined from both the geometrical form and material properties. Many studies of tendon and ligament include a mechanical assessment of the structure in vitro. However, to determine the material properties of the constituent tissues it is necessary to measure cross-sectional area (CSA). Problems associated with this include damage to the structure, inaccurate values for non-uniform shapes, labour intensive techniques or requirement of expensive equipment. We describe a non-destructive technique for measurement of tendon and ligament CSA based on that of Race and Amis (J. Biomech. 29 (1996) 1207). The modified technique uses aqueous rapid curing alginate dental impression paste, digital photography and computerised image analysis. This technique is quick and simple to carry out and provides accurate values (within 0.8%) for CSA which are reproducible (coefficient of variation = 1.42%). The technique is non-destructive and can be used on specimens with an irregular shape.