Influence of novocaine blockade on the level of calcium and phosphorus in the blood of patients with fractures of long bones

In bone tissue, calcium is in the form of deeply located, hardly soluble crystals of bone apatite - ${\mathrm{Ca}}_{10}{\left({\mathrm{PO}}_4\right)}_6{\left(\mathrm{OH}\right)}_2$, covered with a layer of relatively easier soluble forms of calcium compounds. This outer layer of calcium compounds plays, according to Howard (1957), the role of a "calciostat", that is, a tissue that ensures the constancy of Ca levels in the blood. There is a constant exchange of Ca ions between this layer of bone tissue and blood. When the existing balance is disturbed and the release of Ca ions from the bone tissue decreases, hypocalcemia occurs, and with an increase, hypercalcemia occurs. Phosphorus is found in bone tissue mainly in the form of tribasic calcium phosphate.