intraarticular ligament, a ligament that forms part of the joints between 16 of the 24 ribs, dividing the joints into two cavities, each containing a synovial membrane. Each intraarticular ligament consists of a short, flattened band of fibers inside the joint, attached by one extremity to the rib and by the other to the intervertebral disk. Intraarticular ligaments are not present in the joints of the first, tenth, eleventh, and twelfth ribs, each of which has only one synovial cavity. Compare radiate ligament.
