The incus (plural: incudes) is the middle of the three ossicles articulating with the head of the malleus anteromedially, forming the incudomalleolar joint, and the stapes inferomedially, forming the incudostapedial joint.
Named parts include:
- a body which articulates with the head of the malleus, and to which the superior ligament of the incus is attached (to the roof of the middle ear cavity)
- a long crus (or process) down to the lentiform process (a.k.a. lentiform nodule) which articulates with the head of the stapes
- a short crus (or process) to which the posterior ligament of the incus is attached
The long crus is the most frequently eroded part of any of the ossicles.
History and etymology
Incus is derived from the Latin word incus meaning anvil.