Morphometric evaluation of chondrocyte cavities in normal and prearthrotic human femoral heads.

In 25 human femoral heads, the structural changes in the chondrocyte cavities of prearthrotic cartilage were determined in three different layers by detailed morphometric evaluation. As examination parameters, the area, perimeter, diameter, and the form deviation from a circle (form PE) were chosen. In addition, we calculated the numeric cell density and the mean distance between two chondrocyte cavities. For intraindividual comparison, the same data were obtained from nondegeneratively changed cartilage areas of each femoral head. The main arthrotic regions were located in the weight-bearing area of the femoral head, particularly in the dorso- and ventrolateral quadrants. The number of chondrocyte cavities as well as the numeric cell density were decreasing from superficial to basal layers, whereas the mean distance between two chondrocyte cavities was increasing. Concerning these parameters, no significant differences were seen between the prearthrotic and control groups. We found that the chondrocyte cavities in the superficial layer in prearthrotic areas show a tendency to smaller volumes in comparison with nondegeneratively changed areas, whereas in the basal layer, no difference could be seen. We presume that the changes in the articular cartilage are not related to an insufficient supply of the cartilage with nutriments, but probably to the high mechanical strain applied to its surface.