Which bone is labeled E on a wrist radiograph?

Which bone is labeled E on a wrist radiograph?

• A. Hamate
• B. Trapezium
• C. Trapezoid
• D. Capitate

Answer: (B)

On a wrist radiograph, identify carpal bones by their positions in two rows. In the distal row, moving from the thumb side toward the little finger, the order is trapezium, trapezoid, capitate, hamate. The bone at the radial (thumb) edge of this row is the trapezium, and it has a distinctive saddle-shaped articular surface for the first metacarpal, which forms the carpometacarpal joint of the thumb. This characteristic shape and location help distinguish it from the others: the trapezoid is next to it medially, the capitate sits centrally and is larger, and the hamate lies on the ulnar side with a hook-like hamulus. Therefore, the bone labeled at the thumb-side of the distal carpal row is the trapezium.

On a wrist radiograph, identify carpal bones by their positions in two rows. In the distal row, moving from the thumb side toward the little finger, the order is trapezium, trapezoid, capitate, hamate. The bone at the radial (thumb) edge of this row is the trapezium, and it has a distinctive saddle-shaped articular surface for the first metacarpal, which forms the carpometacarpal joint of the thumb. This characteristic shape and location help distinguish it from the others: the trapezoid is next to it medially, the capitate sits centrally and is larger, and the hamate lies on the ulnar side with a hook-like hamulus. Therefore, the bone labeled at the thumb-side of the distal carpal row is the trapezium.