Ossicular chain disruption

Ossicular chain disruption (or ossicular discontinuity) is loss of normal alignment between the three inner ear ossicles. The condition is a cause of conductive hearing loss.

Exact incidence and prevalence are not known. Hearing loss associated with temporal bone fractures in children occurs in 75%, but persists beyond 1 month in less than 15%.

Sudden conductive hearing loss in traumatic cases. The hearing loss may be due to ossicular chain disruption or middle ear haemorrhage. Sensorineural hearing loss may coexist, e.g. in temporal bone fractures that have a transverse component.

Ancillary features include haemotympanum and/or otorrhoea.

Causes are:

Temporal bone CT

Loss of normal joint alignments: 

  • incus and malleus are normally closely apposed, resembling a scoop of ice cream in a cone with the malleus representing the ice cream and the incus represents the cone
CT - virtual endoscopy

3D reconstruction aids surgical planning.

Conductive hearing loss of more than 30 dB persisting six months post injury is considered an indication of reconstruction of the ossicular chain:

  • surgical (acute or delayed) - relocation; reconstruction with hydroxyapatite prosthese; cartilage allografts
  • conservative - hearing aids
Share article

Article information

rID: 23289
Tag: trauma
Synonyms or Alternate Spellings:
  • Ossicular discontinuity
  • Disruption of the ossicular chain

Support Radiopaedia and see fewer ads

Cases and figures

  • Drag
    Figure 1: with temporal bone fracture
    Drag here to reorder.
  • Drag
    Case 1
    Drag here to reorder.
  • Drag
    Case 2
    Drag here to reorder.
  • Drag
    Case 3: incudo-mallear joint disruption
    Drag here to reorder.
  • Drag
    Case 4
    Drag here to reorder.
  • Updating… Please wait.

    Alert accept

    Error Unable to process the form. Check for errors and try again.

    Alert accept Thank you for updating your details.