Otosclerosis (Otospongiosis)

Jeffrey D. Wolfrey, MD and Kellie D. Wheeler, MD Reviewed 06/2017

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Subject: Otosclerosis (Otospongiosis)

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  • A primary bone dyscrasia involving the otic capsule

  • This is the leading cause of conductive hearing loss in adults.

  • There are two forms:

    • Histologic otosclerosis: asymptomatic form in which abnormal bone spares vital structures of the ear

    • Clinical otosclerosis: Abnormal spongy bone involves ossicular chain or other structures, leading to altered physiology.

  • System(s) affected: sensory, hearing



  • Predominant age

    • Clinical onset usually in early 20s

    • Peak incidence 3rd to 5th decade

  • Predominant gender: female > male (2:1)

Pregnancy Considerations

  • Progression may accelerate during pregnancy.

  • Some women first notice hearing loss at this time.



  • Histologic form: 4–8% among U.S. Caucasian population; 1% among African Americans

  • Histologic form: U.S. Caucasian population: 5,000/100,000; African Americans: 1,000/100,000

  • Clinical form: 0.3–0.4%


  • Unknown; possible association with measles virus infection and hormonal factors

  • Fluoride metabolism may play a role; fluoride treatment is under investigation, as early results demonstrate improved hearing outcomes.


  • 50–60% of those affected give positive family history.

  • Appears to be transmitted by autosomal dominant gene with variable expressivity


Unknown, possibly measles virus infection 


  • Van der Hoeve syndrome (rare triad of osteogenesis imperfecta, blue sclera, and otospongiosis)

  • Tinnitus, usually low frequency



  • Progressive conductive hearing loss, usually with well-preserved speech discrimination

  • Patients often are soft-spoken and aware that they seem to hear better in noisy environments.


Schwartze sign: reddish hue in front of oval window; on promontory at otoscopic exam 


  • Chronic suppurative otitis media

  • Serous otitis media

  • External auditory canal occlusion

  • Ménière disease

  • Ossicular chain disruption

  • Congenital fixation of stapes

  • Paget disease of bone

  • Presbycusis

  • Advanced otosclerosis mimics sensorineural deafness.


Coaxial or CT scan sometimes helpful 


Tuning fork and audiometric testing for conductive and/or sensorineural hearing loss 
  • Will lateralize to more impaired ear with Weber test

  • Conductive hearing loss; may be as severe as the 60 dB maximum

  • May have sensorineural hearing loss with cochlear involvement

  • Carhart notch: a dip in bone conductive threshold at 2,000 Hz on audiometric testing


  • Gross

    • Off-white to reddish bone formation, most often located anterior to the oval window and extending to involve the stapedial footplate; sometimes covers entire oval window (obliterative); may be found anywhere in otic capsule

    • Bilateral in 75% of patients

  • Micro

    • Spongy-appearing bone with increased vascular spaces

    • Osteoblasts and osteoclasts are plentiful.


  • Important differential diagnosis for presbycusis

  • Surgical results similar in older versus younger patient cohorts (1)[A].




No specific drug therapy, but sodium fluoride, bisphosphonates, vitamin D, and calcium gluconate have been tried, especially in cases of predominantly sensorineural hearing loss. 


  • Surgical correction (stapedotomy/stapedectomy)

    • Usually involves mobilization or removal of the stapedial footplate with placement of a stapes prosthesis

    • Recent procedural innovations have involved use of lasers.

    • Cochlear implantation may achieve better results in advanced cases, but systematic reviews in 2014 and 2016 support initial stapes surgery with cochlear implantation reserved for those with unsatisfactory improvement in hearing and speech recognition (2,3,4)[A].

    • Hearing aids may be helpful postsurgery (5)[B].

  • Relative indications for surgery include negative Rinne test (air–bone audiometric gap at least 20 dB) and bilateral involvement.



  • No restrictions on activity

  • Hearing aids


Interval audiometric testing 


  • Because speech discrimination is usually preserved, patients should be advised of the possible benefit from hearing aids as an alternative or adjunct to surgery.

  • Mayo Foundation for Medical Education and Research, Section of Patient and Health Education, Sieber Subway, Rochester, MN 55905; (507) 284-8140

  • MedlinePlus. Otosclerosis: http://www.nlm.nih.gov/medlineplus/ency/article/001036.htm


  • Progressive hearing loss if not treated; 10% develop sensorineural hearing loss

  • Surgery closes air–bone gap to 10 dB in >90% of cases (6)[B].

  • Surgical results are durable in case series with >30 years of follow-up.

  • Some decline over time and may benefit from repeat surgical intervention.


Surgical risks include chorda tympani nerve injury, tympanic membrane laceration, ossicular chain disruption, otitis media and externa, labyrinthitis, granuloma formation, perilymph fistulas, and total deafness (“dead ear”). 


Meyer TA, Lambert PR. Primary and revision stapedectomy in elderly patients. Curr Opin Otolaryngol Head Neck Surg.  2004;12(5):387–392.  [View Abstract]
Kabarra B, Gauche C, Calmels MN et al. Decisive criteria between stapedectomy and cochlear implantation in patients with far advanced otosclerosis. Otol Neurotol.  2015;36(3):e73–e78.  [View Abstract]
Abdurehim Y, Lehmann A, Zeitouni AG. Stapedectomy vs cochlear implantation for advanced otosclerosis: systematic review and meta-analysis [published online ahead of print June 21, 2016]. Otolaryngol Head Neck Surg.  [View Abstract]
van Loon MC, Merkus P, Smit CF et al. Stapedotomy in cochlear implant candidates with far advanced otosclerosis: a systematic review of the literature and meta-analysis. Otol Neurotol.  2014;35(10):1707–1714.  [View Abstract]
Redfors YD, Hellgren J, Möller C. Hearing-aid use and benefit: a long-term follow-up in patients undergoing surgery for otosclerosis. Int J Audiol.  2013;52(3):194–199.  [View Abstract]
Vincent R, Sperling NM, Oates J et al. Surgical findings and long-term hearing results in 3,050 stapedotomies for primary otosclerosis: a prospective study with the otology-neurotology database. Otol Neurotol.  2006;27(8 Suppl 2):S25–S47.  [View Abstract]


  • Derks W, De Groot JA, Raymakers JA et al. Fluoride therapy for cochlear otosclerosis? An audiometric and computerized tomography evaluation. Acta Otolaryngol.  2001;121(2):174–177.  [View Abstract]

  • Ealy M, Smith RJ. Otosclerosis. Adv Otorhinolaryngol.  2011;70:122–129.  [View Abstract]

  • Marchese MR, Paludetti G, De Corso E et al. Role of stapes surgery in improving hearing loss caused by otosclerosis. J Laryngol Otol.  2007;121(5):438–443.  [View Abstract]

  • Potocka-Bakłażec M, Sakowicz-Burkiewicz M, Kuczkowski J et al. Expression of TNF-α, OPG, IL-1β and the presence of measles virus RNA in the stapes of the patients with otosclerosis. Eur Arch Otorhinolaryngol.  2015;272(8):1907–1912.  [View Abstract]


Hearing Loss 



  • H80.90 Unspecified otosclerosis, unspecified ear

  • H80.20 Cochlear otosclerosis, unspecified ear

  • H80.00 Otosclerosis w oval window, nonobliterative, unsp ear

  • H80.10 Otosclerosis involving oval window, obliterative, unsp ear

  • H80.81 Other otosclerosis, right ear

  • H80.01 Otosclerosis w oval window, nonobliterative, right ear

  • H80.02 Otosclerosis w oval window, nonobliterative, left ear

  • H80.03 Otosclerosis involving oval window, nonobliterative, bi

  • H80.11 Otosclerosis involving oval window, obliterative, right ear

  • H80.12 Otosclerosis involving oval window, obliterative, left ear

  • H80.13 Otosclerosis involving oval window, obliterative, bilateral

  • H80.21 Cochlear otosclerosis, right ear

  • H80.22 Cochlear otosclerosis, left ear

  • H80.91 Unspecified otosclerosis, right ear

  • H80.80 Other otosclerosis, unspecified ear

  • H80.82 Other otosclerosis, left ear

  • H80.83 Other otosclerosis, bilateral

  • H80.93 Unspecified otosclerosis, bilateral

  • H80.92 Unspecified otosclerosis, left ear

  • H80.23 Cochlear otosclerosis, bilateral


  • 387.9 Otosclerosis, unspecified

  • 387.2 Cochlear otosclerosis

  • 387.0 Otosclerosis involving oval window, nonobliterative

  • 387.1 Otosclerosis involving oval window, obliterative

  • 387.8 Other otosclerosis


  • 11543004 Otosclerosis (disorder)

  • 91108004 Cochlear otosclerosis

  • 62856000 Nonobliterative otosclerosis involving oval window (disorder)

  • 55664001 Obliterative otosclerosis involving oval window (disorder)


  • The audiometric signature of otosclerosis is a dip in conductive hearing at 2,000 Hz.

  • Hearing aids are helpful in patients with preserved speech discrimination.

  • Bilateral involvement and an air–bone audiometric gap of ≥20 dB are indications for surgery.

  • Surgical correction has a high success rate with good long-term durability.