Principal types of functional architecture of cancellous bone in man.

The cancellous bone architecture in man is locally specific. Several principal types can be distinguished, depending on the kind of loading and movement in the joint in one, two or more directions. Under multidirectional load the spongiosa trabeculae form spatial fans seen as two crossing systems on plane sections. Marked differences exist between the bone structure under concave joint surfaces and the convex ones. The analysis testifies the correctness of the author's own theory on the development of the cancellous bone architecture. According to this theory every trabecular system corresponds to other direction of maximal principal stress in the course of movement. Both crossing systems in the metaphysis are pressure systems, corresponding to opposite extreme positions in the joint. Tension systems can be found in sites of ligament or tendon insertions and closely under concave articular surfaces only.