1. In many cases of ununited fractures, there is as an underlying basis a constitutional disturbance responsible for the condition, demonstrable as a deficiency in the inorganic bone-forming elements of the blood.
2. This deficiency shows itself as either a low phosphorus or a low calcium, in most instances the former. In those patients presenting a low phosphorus there is usually an abundant callus, but no calcification; whereas those patients with low calcium usually show little or no callus.
3. No healing of the fracture takes place when the inorganic constituents, calcium and phosphorus, are so reduced that the product of these elements is less than thirty; little healing takes place between thirty and thirty-five; active healing results with a product between thirty-five and forty.
4. Patients with ununited fractures in whom there is a deficiency of one or the other of these elements will, when the deficiency is compensated, go on to healing.
