During which phase of fracture healing does inflammation occur?

Inflammation is a critical and initial response that occurs immediately following a fracture and extends for several days post-injury. During this phase, the body reacts to the injury by increasing blood flow to the site, which helps to bring in essential immune cells and nutrients that facilitate healing. The inflammatory phase typically lasts from the moment of the injury up to about five days after.

This phase is characterized by the formation of a hematoma at the fracture site, which serves as a foundation for subsequent healing processes. Inflammatory mediators play a key role in signaling and managing the next phases, including the formation of a soft callus and ultimate hard callus during the healing process. Recognizing that inflammation is vital for initiating the repair process helps underscore its importance in the overall healing timeline.

The other phases outlined in the options represent different stages of healing. The period marked as 5 to 21 days involves the soft callus formation andangiogenesis, while the following phase of 21 days to 18 months encompasses the hard callus formation and remodeling. The option that mentions surgery refers to a specific intervention point but does not encompass the natural inflammatory response that is initiated immediately after a fracture.