Which description best differentiates a flail chest from a simple rib fracture?

Which description best differentiates a flail chest from a simple rib fracture?

• A. Flail chest involves multiple broken ribs that prevent proper chest expansion
• B. A simple rib fracture causes no pain
• C. Flail chest is always accompanied by skull fracture
• D. A rib fracture always requires surgery

Answer: (A)

The key idea is chest-wall stability and how breathing is affected. Flail chest happens when several adjacent ribs are broken in multiple places, creating a detached segment of the chest wall. That loose segment moves opposite to the rest of the chest during breathing (paradoxical movement) and disrupts normal chest expansion, making ventilation inefficient. A simple rib fracture, on the other hand, is typically a single rib break that doesn’t compromise the overall mechanics of the chest wall, even though it’s painful and can limit breathing because of pain. The other statements don’t fit: skull fractures aren’t a requirement of flail chest; rib fractures commonly cause pain and don’t inherently involve no pain; and surgery isn’t always needed for rib fractures—most are treated without operative intervention.