Incus

Last revised by Dr Francis Deng on 17 Nov 2021

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.

Four parts of the incus are named:

  • body
    • contiguous with the short and long processes
    • articulates with the head of the malleus
    • attaches the superior ligament of the incus (to the roof of the middle ear cavity)
  • long process (or crus)
    • contiguous with the body and lentiform process
  • lentiform process (or lentiform nodule)
    • contiguous with the long process
    • articulates with the head of the stapes
  • short process (or crus) 
    • contiguous with the body
    • attaches the posterior ligament of the incus

History and etymology

Incus is derived from the Latin word incus meaning anvil.

Related pathology

The long crus is the most frequently eroded or resorbed part of the ossicles.

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1: incus
    Drag here to reorder.
  • Figure 2: anatomy of the middle ear
    Drag here to reorder.
  • Figure 3: annotated CT
    Drag here to reorder.
  • Figure 4: middle ear anatomy illustrations
    Drag here to reorder.
  • Figure 5: middle ear anatomy illustrations
    Drag here to reorder.