THE GROSS AND HISTOLOGIC ANATOMY OF THE SCAPHOLUNATE INTEROSSEOUS LIGAMENT

The scapholunate interosseous ligament, which connects the carpal scap hoid and lunate bones, was evaluated by gross dissection and serial hi stologic sections in transverse, sagittal, and coronal planes in 21 fr esh and 16 fixed adult cadaver wrists. The scapholunate interosseous l igament is consistently divisible into three anatomic regions: dorsal, proximal, and palmar. The dorsal region is thick and composed of shor t, transversely oriented collagen fibers. The proximal region is princ ipally composed of fibrocartilage, with a few superficial, longitudina lly oriented collagen fibers. The proximal region may extend distally a few millimeters into the scapholunate joint space, thus resembling a knee meniscus. The radioscapholunate ligament separates the proximal and palmar regions of the scapholunate interosseous ligament, often ex tending distally to cover the dorsal surface of the palmar region of t he scapholunate interosseous ligament. The palmar region is thin and c omposed of obliquely oriented collagen fascicles, just dorsal to and s eparate from the long radiolunate ligament.