The oblique cord is a ligament between the ulna and radius. It takes the form of a small, flattened band, extending downward and lateralward, from the lateral side of the ulnar tuberosity at the base of the coronoid process to the radius a little below the radial tuberosity. Its fibers run in the opposite direction to those of the interosseous membrane of the forearm.
Left elbow joint, showing anterior and ulnar collateral ligaments. The oblique cord visible as a diagonal white line near the center bottom.
The oblique cord is called by other names including oblique ligament, chorda obliqua, radio-ulnar ligament, chorda oblique antebrachii anterior, proximal interosseous band, dorsal oblique accessory cord, proximal band of the interosseous membrane, superior oblique ligament, oblique ligament proper, round ligament, and ligament of Weitbrecht.
It has no known function and can be cut without apparent consequence.