Bone Biology
A 40-year-old man sustains a mid-shaft femur fracture treated with intramedullary nailing allowing some motion at the fracture site. At 3-week follow-up, radiographs show periosteal new bone formation and soft callus. By 8 weeks, the callus is mineralizing and becoming hard callus. At 6 months, the fracture line is obscured and the bone is remodeling. His orthopaedic registrar asks about the biology of fracture repair. Regarding fracture repair biology:
Mark each as TRUE or FALSE
Fracture healing occurs by two mechanisms: primary (direct/cortical) healing with absolute stability...
The inflammatory phase (days 1-7) involves hematoma formation, cytokine release (IL-1, IL-6, TNF-Ī±),...
Primary healing is the natural mechanism of all fractures; secondary healing only occurs with absolu...
The hard callus phase (weeks 4-12) involves mineralization of the soft callus and replacement with w...
Factors affecting fracture healing include blood supply (most important), degree of stability (too m...
Answer the questions to see explanations
Click T (True) or F (False) for each option