The nature of bones and joints: a new perspective.

In human ontogeny recapitulating phylogeny, bones arrive late on the scene--long after neurogenesis, musculogenesis, organogenesis and so on are over--as islands of ossification in an ocean of collagen. This study confirms this developmental sequence by demonstrating, in cadavers, the rather independent nature of bone, to which nothing--muscle, tendon, ligament or articular cartilage--is attached. Bone is like the air in a tubeless tyre; it gives rigidity and shape to the tyre, and in return takes the shape of the tyre. The tibia, for example, is the bony tissue that is contained in tyre-like casing made of peritibial soft tissues whose inner limit is the periosteum, which continues proximally and distally as capsules of knee/ankle joint, and to which only are the articular cartilages of the knee and ankle attached, being clearly free from the bones. This study also exposes the truer nature of a joint wherein the articular cartilage assumes anatomic and physiologic significance hitherto unthought of.