The elbow-joint is a ginglymus or hinge-joint. The trochlea of the humerus is received into the semilunar notch of the ulna, and the capitulum of the humerus articulates with the fovea on the head of the radius. The articular surfaces are connected together by a capsule, which is thickened medially and laterally, and, to a less extent, in front and behind. These thickened portions are usually described as distinct ligaments under the following names:
The Ulnar Collateral.
The Radial Collateral.
FIG. 329 Left elbow-joint, showing anterior and ulnar collateral ligaments. (See enlarged image)
FIG. 330 Left elbow-joint, showing posterior and radial collateral ligaments. (See enlarged image)
The Anterior Ligament (Fig. 329).The anterior ligament is a broad and thin fibrous layer covering the anterior surface of the joint. It is attached to the front of the medial epicondyle and to the front of the humerus immediately above the coronoid and radial fossæ below, to the anterior surface of the coronoid process of the ulna and to the annular ligament (page 324), being continuous on either side with the collateral ligaments. Its superficial fibers pass obliquely from the medial epicondyle of the humerus to the annular ligament. The middle fibers, vertical in direction, pass from the upper part of the coronoid depression and become partly blended with the preceding, but are inserted mainly into the anterior surface of the coronoid process. The deep or transverse set intersects these at right angles. This ligament is in relation, in front, with the Brachialis, except at its most lateral part.