In a standard lateral elbow view, what indicates a possible radial head fracture?

• A. Fat pad sign
• B. Smith sign
• C. Bennett sign
• D. Colles sign

Answer: (A)

In a standard lateral elbow view, the presence of the fat pad sign is indicative of a possible radial head fracture. The fat pad sign refers to the visibility of the anterior fat pad and possibly the posterior fat pad on an x-ray. Normally, these fat pads are not visible; however, when there is an effusion in the joint, often due to trauma or fracture, the fat pads become displaced and are seen as elevated. This displacement is commonly associated with injuries to the elbow, particularly to the radial head, as the joint effusion can occur in response to a fracture in that area. Consequently, detecting the fat pad sign on an x-ray becomes a crucial diagnostic feature suggesting that there may be a radial head fracture, making it the correct answer in this context.

The other options listed, while relevant to different fractures or injuries, do not pertain to the indication of a radial head fracture. The Smith sign is related to fractures of the distal radius, the Bennett sign pertains to injuries at the base of the first metacarpal, and the Colles sign is associated with distal radius fractures with dorsal angulation. Each of these signs signifies different types of injuries and is not applicable to the assessment of the elbow joint.