Anatomy and function of the palmar aponeurosis pulley.

The transverse fibers of the palmar aponeurosis are attached by vertical septa to the underlying transverse metacarpal ligament and thus form a pulley over the flexor tendons. It is a constant and substantial retinacular structure that overlays the synovial sheath. Because of its proven function, position and breaking strength, I believe it should be considered part of the flexor tendon pulley system.