Exam 2 Review: Chapter 6: Bone Fractures
bone fracture - Any clinically-significant break in a bone; in the first several decades of life, usually due to a trauma, but in old age, usually due to osteoporosis. [See Fig. 6.14, p. 191]
fracture hematoma - The localized inflamed painful swelling filled with clotted blood resulting from a break in a blood vessel (within the bone, the marrow space, the periosteum, or the surrounding tissue) associated with a bone fracture; it represents the first stage in repair of a bone fracture.
procallus = fibrocartilaginous callus = soft callus - the first stage (approximately one week) in the healing of a bone fracture; connective tissue stem cells and capillary blood vessels penetrate the inflamed fracture hematoma and as phagocytes clear the debris from the injury, new fibrous connective tissue matrix, then new cartilage matrix, and finally new bone matrix begin to form; the procallus material usually extends beyond the volume previously occupied by the uninjured bone; it represents the second stage in repair of a bone fracture.
bony callus = hard callus - the second, final stage (several weeks to months in duration) in the healing of a bone fracture; osteoclasts continue to dissolve away the fibrous and cartilaginous components of the injury site while osteoblasts continue to replace that material with new bone matrix; bone remodeling will continue until the normal dimensions and composition of the bone are recreated; it represents the third and final stage in repair of a bone fracture, though some additional bone remodelling will often follow over time.