The extensor retinaculum is a strong, fibrous band, extending obliquely downward and medialward across the back of the
wrist. On the dorsal side of the hand, the
palmar carpal ligament corresponds in location and structure to the extensor retinaculum, both being formations of the antebrachial fascia and therefore continuous. Consequently, the
flexor retinaculum is commonly referred to as the
transverse carpal ligament to avoid confusion.
Histology Structurally, the retinaculum consists of three layers. The deepest layer, the gliding layer, consists of
hyaluronic acid-secreting cells. The thick middle layer consists of interspersed elastin fibers, collagen bundles, and fibroblasts. The most superficial layer is made up of loose connective tissue which contains vascular channels. Combined these three layers create a smooth gliding surface as well as mechanically strong tissue which prevents tendon bowstringing. The extensor retinaculum of the foot has similar structure. ==Clinical significance ==