Accurate determination of the biomedical properties of connective tissue such as tendons and ligaments is dependent on the accurate measurement of their cross-sectional area (CSA). To date, techniques for determining cross-sectional areas of ligaments and tendons have been less than ideal due to their complex geometries and their deformations under external load. A novel non-destructive technique has been developed for determining the cross-sectional area of tendon by locating the tendon rupture, in which aqueous rapid curing alginate dental molding materials, digital photography and computerized image analysis are utilized. This technique marks tendons and alginate molds at 1 cm interval and then tendons are taken out for tensile test. Real-time video is recorded to locate the position of tendon rupture. The corresponding alginate slice is found and then analysis through computer image processing software to obtain a more accurate CSA at tendon rupture, which can be used to calculate the stress and young's modulus of tendon. The accuracy of this technique has been investigated and comparisons have been made with the alginate un-localization molding technique and ellipse estimation technique. Results show this technique can provide accurate CSA values (within 2%) and great reproducibility (coefficient of variation = 0.8%). The technique is non-destructive, can obtain morphological information of soft tissue and can detect cavities.
Keywords: Alginate; Area measurement; Biomechanics; Cross-sectional area; Human tendon; Moulding technique.