The thickness of the calcified layer of articular cartilage

The thickness of both the articular cartilage and its calcified zone were measured at 25 carefully selected points in 8 human femoral heads, and the ratio of one to the other was found to be remarkably constant for each bone. The thickness of the calcified zone therefore shows the same distribution pattern as that of the total cartilage and, since the latter is dependent upon the distribution of the load, the thickness of the calcified region also appears to be related to mechanical stress. The volume of the calcified zone, however, expressed as a percentage of the total cartilage, varied considerably from one bone to another within the range from 3.23 to 8.8%. Too few specimens were examined to allow correlation with age or sex to be either refuted or confirmed