Bone Callus

Etiology and pathophysiology

The process of fracture consolidation occurs in several strictly sequential stages. Initially, blood that has escaped from damaged vessels coagulates, forming a clot that attracts the body’s reparative cells. Within a few weeks, this clot is replaced by dense cartilaginous tissue. At this stage, the fragments are already “glued” together, but mechanical strength is still absent.

Subsequently, specialized cells mineralize cartilage with calcium, transforming it into woven bone. The final stage involves prolonged remodeling, where the coarse callus is restructured into a strong lamellar structure that is aligned with physical stress lines.

Clinical significance

The appearance of a characteristic cloudy shadow around the fracture zone on radiographs indicates the successful onset of the healing process. Complete ossification of the callus is the main clinical criterion for removing the cast or allowing full load bearing on the leg.

In medical practice, pathological types of calluses are also encountered, the most clinically significant being hypertrophic and atrophic. A hypertrophic callus occurs with excessive fragment mobility, appearing as a large bony mass. An atrophic callus develops with extremely poor local blood supply and often indicates the formation of a false joint.