The structure that articulates with the capitulum to form the elbow joint is which option?

• A. Capitulum
• B. Olecranon process
• C. Radial head
• D. Ulnar head

Answer: (C)

The elbow joint includes a key articulation where the distal humerus meets the radius. The rounded capitulum of the distal humerus fits with the head of the radius, forming the radiocapitellar joint that’s part of the elbow complex. This pairing enables not only bending of the elbow but also rotation of the forearm. The olecranon process of the ulna interacts with the humerus at the back of the joint, and the distal radioulnar joint involves the ulna’s head with the radius, not the capitulum. So the structure that articulates with the capitulum is the radial head.