Otosclerosis

• Otosclerosis


  A condition where there is remodelling of the small bones in the middle ear, leading to conductive hearing loss
• Otosclerosis

  • Usually presents before the age of 40 years
  • Thought to result from a combination of environmental and genetic factors
  • Can be inherited in an autosomal dominant pattern
  • More common in women
• Pathophysiology of otosclerosis


  1. Abnormal bone remodelling and formation affects the auditory ossicles, mainly the base of the stapes where it attaches to the oval window

  2. Causes stiffening and fixation of the stapes, preventing effective transmission of sound vibrations to the cochlea

  3. Leads to conductive hearing loss
• Auditory ossicles


  The tiny bones in the middle ear that transmit sound vibrations from the tympanic membrane to the cochlea (malleus, incus, stapes)
• Presentation of otosclerosis


  • Unilateral or bilateral hearing loss
  • Tinnitus
  • Affects lower-pitched sounds more than higher-pitched sounds
  • Female speech may be easier to hear than male speech
  • Patient may talk quietly due to their voice sounding loud compared to the environment
• Examination findings in otosclerosis

  • Otoscopy is normal
  • Weber's test is normal if bilateral, or louder in the more affected ear if unilateral
  • Rinne's test shows conductive hearing loss
• Investigations for otosclerosis


  1. Audiometry shows conductive hearing loss pattern with normal bone conduction and elevated air conduction

  2. Tympanometry shows reduced sound admittance

  3. High-resolution CT scans can detect bony changes
• Management options for otosclerosis

  • Conservative with hearing aids
  • Surgical (stapedectomy or stapedotomy)
• Stapedectomy

  Surgical procedure involving removal of the entire stapes bone and replacement with a prosthesis
• Stapedotomy

  Surgical procedure involving removal of part of the stapes bone, leaving the footplate attached to the oval window, and insertion of a prosthesis