Chondrocyte distribution in the articular cartilage of human femoral condyles.

The distribution of chondrocytes throughout the total thickness of articular cartilage from the femoral condyles of infants, children and adults has been studied using serial sections cut parallel as well as perpendicular to the articular surface. The thickness of the articular cartilage was estimated in fixed sections. In one of the adult specimens, the thickness of the articular cartilage was estimated firstly by direct measurement of the cut surfaces of a series of blocks cut from both condyles and then from the number of parallel sections of the cartilage prepared from those blocks. Cell density was highest in the superficial zone of all specimens examined, declining to lower values in the deep zone of the cartilage. Within this pattern the infant specimens had the highest values for cell density and the adults the lowest, with values for children in an intermediate range. There was no significant variation in cell density across the condyles of the selected adult specimen. The absolute values for cartilage thickness depended on the method used, but in general total thickness was found to approximately double from late gestation to maturity. In the selected adult specimen, the cartilage was thickest just anterior and posterior to the main weight-bearing area of the condyles.