Bone growth in health and disease

Abstract

I have demonstrated the growth pattern characteristic of health in the bone of the young child, not too easy to determine, and its modification under the stress of severe illness and shown that in times of prosperity bone-forming cells grow big and crowd the bone surfaces and are producing bone rapidly, but in times of severe illness they give up their activity, shrink and revert to other forms and disappear until the trabeculae look almost bare; the picture of extreme cellular activity in a few days changes to an almost complete inertia. The study has made clear that one must think of bone, in the early period of life certainly, not as an inert tissue, but as a buzzing hive of activity and also as a highly sensitive tissue, adapting itself rapidly to variations in the general well being and so constituted that in times of special strain it can relinquish its growth activity entirely and relieve the general economy by elimination of that added burden. One must also think of growth in bone as not necessarily a continuous process but rather as one linked closely to the general state and subject to exacerbations and checks and rises and falls in rate to correspond with variations in the latter. Finally, I have shown, with reference to growth under environmental conditions in common, that the cartilage cell and the osteoblast can behave very differently, even oppositely, and in pointing out the differences I have tried to make clear what the lines of arrested growth of the cartilage and the growth retardation lattice, both of which are visible in the x-ray film, actually were and how each came into being and how they both depended on opposite combinations of divergencies in the growth operation of the two tissues.