Humeroradial joint

The humeroradial joint is the joint between the head of the radius and the capitulum of the humerus, is a limited ball-and-socket joint, hinge type of synovial joint.The radiocapitellar line is used in the detection of radial head dislocation on lateral X-rays. It normally goes through the capitulum of the humerus.Abnormally pointed radiocapitellar line, indicating radial head dislocation.Capsule of elbow-joint (distended) seen from frontCapsule of elbow-joint (distended) seen from backLeft elbow-joint showing anterior and ulnar collateral ligamentsLeft elbow-joint showing posterior and radial collateral ligaments The humeroradial joint is the joint between the head of the radius and the capitulum of the humerus, is a limited ball-and-socket joint, hinge type of synovial joint. The annular ligament binds the head of the radius to the radial notch of the ulna, preventing any separation of the two bones laterally. Therefore, the humeroradial joint is not functionally a ball and socket joint, although the joint surface in itself allows movement in all directions The annular ligament secures the head of the radius from dislocation, which would otherwise tend to occur, from the shallowness of the cup-like surface on the head of the radius. Without this ligament, the tendon of the biceps brachii would be liable to pull the head of the radius out of the joint.