Boxer's fracture describes a fracture of which bone?

• A. Radius
• B. Ulna
• C. First metacarpal
• D. Fifth metacarpal

Answer: (D)

Boxer’s fracture is a fracture of the neck of the fifth metacarpal, the bone that forms the little finger side of the hand, typically resulting from punching a hard object with a clenched fist. This specific location—near the knuckle of the little finger—defines the injury and distinguishes it from fractures of the forearm bones or the thumb. The fifth metacarpal is the one most directly involved when the hand strikes something with a closed fist, hence the name. Fractures of the radius or ulna are common from different trauma mechanisms (like falls onto an outstretched hand), and fractures of the first metacarpal involve the thumb rather than the little finger, so they’re not Boxer's fracture. In this injury, you’d expect pain, swelling, and a deformity at the little-finger knuckle, with imaging showing a neck fracture of the fifth metacarpal.