Fat embolism is a risk after which injuries?

• A. Long bone or pelvic fractures
• B. Rib fractures
• C. Skull fractures
• D. Ankle sprains

Answer: (A)

Fat embolism risk arises when fatty marrow is released into the bloodstream after fractures that disrupt a lot of marrow, especially in long bones and the pelvis. When these bones crack, fat globules can travel to the lungs and other organs, causing respiratory symptoms (dyspnea, hypoxemia) and sometimes changes in mental status or a petechial rash within about 24 to 72 hours. This pattern makes long bone and pelvic fractures the classic scenario for fat embolism. In contrast, rib fractures, skull fractures, or ankle sprains involve less exposure of fatty marrow and are not typically associated with fat embolism, so the risk is much lower for those injuries.