QUANTITATIVE ASSESSMENT OF ARTICULAR-CARTILAGE ROUGHNESS

Articular cartilage is the bearing surface within human joints and as such is a subject of much interest among orthopaedic specialists. Diseases such as osteoarthritis are characterized by a deterioration in the cartilage surface and thus early detection and quantification of surface changes would be advantageous in the study and treatment of such disorders. Differential light scattering was studied as a technique for measuring the roughness of articular cartilage with the aim of developing a minimally invasive measurement method for use in-vivo. The method was established using a range of metal rough surfaces and cartilage surfaces. The results were correlated with stylus measurements. Samples were illuminated, using a helium-neon laser, at an incident angle of 45 degree(s) and the intensity of scattered light measured every 0.5 degree(s) over a 25 degree(s) range. For the cartilage surfaces the best correlation existed between optical parameters, based on a one dimensional moment of light intensity, and the roughness, calculated at a sampling length of 0.1 mm, the accuracy being 67%. The method was sensitive to surface changes during specimen preparation for SEM and was quick and easily interpreted. Differential light scattering is therefore a viable method of measuring the surface quality of articular cartilage