In a recent study of the rôle of the hematoma1 in healing fractures it was shown that bony callus grew readily into a blood clot placed over a slight defect in the radius of a dog. As a result of these studies it seems warranted to state that the hematoma serves an important function in the formation of bony callus: as an indifferent base, a trellis, for the ingrowth of callus; as an irritant, stimulating the rapid development of hyperemia and the formation of new capillaries; as a medium for the retention of a possible enzyme influencing the deposition of calcium salts and the development of osteoid tissue, or as a defense wall against the ingrowth of connective tissue. More than likely all these factors come into play in the complex process of the formation of new bone.
The fragments of a broken bone incapable of producing or utilizing
POTTS WJ. INFLUENCE OF MOTION ON HEALING OF FRACTURES. Arch Surg. 1936;33(1):83-91. doi:10.1001/archsurg.1936.01190010086005