Stapes

The Stapes, so called from its resemblance to a stirrup, consists of a head, neck, two crura, and a base.

• The head (capitulum stapedis) presents a depression, which is covered by cartilage, and articulates with the lenticular process of the incus.
• The neck, the constricted part of the bone succeeding the head, gives insertion to the tendon of the Stapedius muscle.
• The two limbs (crus anterius and crus posterius) diverge from the neck and are connected at their ends by a flattened oval plate, the base (basis stapedis), which forms the foot-plate of the stirrup and is fixed to the margin of the fenestra vestibuli by a ring of ligamentous fibers. Of the two crura the anterior is shorter and less curved than the posterior