[Subarticular spongiosa and its relation to the remaining internal structure of the calcaneus in the human].

The subarticular cancellous bone of the human calcaneus has been investigated in sixty nine cases of known age and sex. In addition eleven calcanei without corresponding informations were used. The three forms of cancellous bone and their threedimensional junctions were analysed by means of the dental burr. It is shown an age bound transformation of the roundmeshed cancellous bone into tubular structures and finally into bone plates or an trabecular network. A tubular construction is presumed as intermediate stage changing by osteolysis into bone plates or trabecular meshwork. The conception of the trajectorial structure presented by Gierse (1976) is more differentiated and enlarged. Considering the calcaneus the normal osteoporosis of old age can be understood to be an age controlled exactly adjusting process. The findings of wide spaced an enlarged cancellous bone elements in a few elder individuals is thought to be a secondary adaptation after preceding normal reduction. Histologic and biometric investigations of this subject will be following.