The surface structure of ageing human articular cartilage: a study by reflected light interference microscopy (RLIM).

The surface contours of the weight-bearing area of the left lateral femoral condyle have been examined in vitro in 26 cadavers by reflected light interference microscopy over the age range 0--47 years. The presence of 4 orders of surface irregularity was confirmed. In addition, measurement of the depth, diameter and frequency of the tertiary order of surface hollows showed that while none of these variables was sex-associated, age-related changes in the variables were present. Multiple regression analysis showed that these changes could be considered in terms of periods of maturation (0--21 years) and ageing (22--50 years) of the cartilage. Focal changes in the surface were observed with advancing age. These changes appeared to be regressive and possibly represent an early stage in cartilage fibrillation.