The effect of calcitonin on fracture healing.

Corrective osteotomy of the long bones may be required in patients with Paget's disease. Experiments on rabbits suggest that the safety of the procedures is of concern while the patient receives Calcitonin. Twenty-four rabbits were divided into 4 groups of 6 animals. Half of each group received maintenance doses of Calcitonin subcutaneously. In all animals the left and right ulnae were osteotomized through middiaphysis. The right ulna was fixed with a "mini" dynamic compression plate. The left ulna was not immobilized. Each group of animals was sacrificed at successive intervals of 3 weeks. Histologically, no difference was found in the healing of the fracture of test or control animals. Radiographically, the fracture line persisted longer in animals receiving Calcitonin (6 weeks vs 3 weeks). All fractures healed by 9 weeks. The fracture line disappeared more rapidly in all the immobilized bones. Based on these observations, administration of Calcitonin is not a contraindication for corrective osteotomy in Paget's disease. Osteotomies should be rigidly fixed to maintain the correction achieved surgically until healing is established.