Detailed anatomy of the articular disc of the distal radioulnar joint.

The articular disc of the distal radioulnar joint anatomy was studied in 109 wrist joints from 64 fresh adult cadavers. The disc is a strong fibrocartilaginous semicircular biconcave structure well adapted to its various functional roles. The length of the disc at its radial attachment varied between 12 and 20 mm (in most cases, 14-16 mm), and the width, measured between the apex and the radial base, varied from 7 to 14 mm, (in most cases, 9-11 mm). The thickness of the dorsal and palmar margins and the ulnar apex varied from 3 to 6 mm (in most cases, 4-5 mm), whereas the thickness of the central part varied from 0.5 to 3 mm (in most cases, 1 mm) and in a number of cases was perforated. Because the incidence of perforations increases progressively with the age of the subjects, the perforations were assumed to be degenerative in nature. Although the articular disc is a definable anatomic entity, it is intimately attached to surrounding elements to form a complex anatomic and functional structure.