This document provides an overview of otosclerosis, including: - It is a primary metabolic bone disease affecting the bones of the middle ear that can cause conductive or sensorineural hearing loss. - The pathophysiology involves abnormal bone remodeling leading to fixation of the ossicles or invasion of the inner ear. - Treatment options include observation, hearing aids, medical management with drugs like sodium fluoride, and surgical procedures like stapedotomy or stapedectomy to restore hearing. - Imaging with CT can help grade the severity of the disease and plan for surgical management when indicated based on the air-bone gap and progression of hearing loss.

1. OTOSCLEROSIS
PRESENTER - DR. Kamal Singh Shekhawat

2. HEADINGS
• HISTORY
• INTRODUCTION
• PATHOPHYSIOLOGY
• AETIOLOGY
• CLINICAL FEATURES
• INVESTIGATIONS
• TREATMENT
• COMPLICATIONSh

3. HISTORY
• Valsalva in 1704 - first to describe hearing loss due to
stapes fixation
• 140 yrs later, Meniere described hearing was temporarily
improved by tapping on the stapes with a small gold rod
• Toynbee – 1841 - described fixation of stapes to margins of
oval window
• Politzer - 1894 - the term coined and histologic features
of Otosclerosis

4. HISTORY OF THE PROCEDURE
1. Mobilization era
a) 1800 – kessel - attempted stapes mobilization without ossicular
chain reconstruction
b) Jack removed the stapes, leaving the oval window open
2. Fenestration era
a) Passow - 1897 - idea of 3rd window , created in promontory and
covered with TM
b) Holmgren – 1923 - created a fistula in HSC and sealed it
immediately with periosteum
c) Sourdille – 1930 - popularized the procedure with his 3-stage
technique
d) Lempert – 1938 - developed a 1-stage technique for HSC
fenestration
• Results, however, were short-lived because the fenestra often
resealed with bone.

5. 3. Stapedectomy era:
a) Rosen – 1952 – accedental stapes mobilization
b) Shea - 1955 - Stapedectomy - Removed the stapes, sealed
the oval window with an autograft vein wall, and then
reconstructed the sound-conducting mechanism with an
artificial prosthesis
4. Stepedotomy era
a) Mayers – 1970s - Stapedotomy using a piston prosthesis
b) Perkins – 1980s - Began using the laser for stapedotomy in a
procedure in which a small hole is made in the footplate

6. INTRODUICTION
Otosclerosis
Primary metabolic bone disease of the otic
capsule and ossicles
Results in fixation of the ossicles and
conductive hearing loss
May have sensorineural component if the
cochlea is involved
Genetically mediated
Autosomal dominant with incomplete
penetrance (40%) and variable expressivity

7. 1. Otic labyrinth.
2. Periotic labyrinth or
perilymphatic labyrinth (or
space)
3. Otic capsule.
(a) Endosteal
(b) Enchondral.
(c) Periosteal.

8. • TYPES:
– ‘Stapedial' otosclerosis: Involves the stapes and clinically
manifested by a CHL with normal TM, the tympanogram
was peaked with normal pressure, with an air-bone gap of
15 dB or more, over 0.5, 1 and 2 kHz
– 'Histologic' otosclerosis: Lesion that does not involve the
stapes, SV joint or cochlear endosteum, is consequently
asymptomatic and can be diagnosed only by post-mortem
examination of the temporal bone.
– 'Cochlear' otosclerosis is a term generally reserved for the
occurrence of pure SNHL due to involvement of cochlea

9. Types of stapedial otosclerosis.
(A) Anterior focus. (B) Posterior focus. (C) Circumferential.
(D) Biscuit type (thick plate). (E) Obliterative

10. EPIDEMIOLOGY
• 0.3 – 0.5% overall prevalence of clinical otosclerosis
% incidence of
Race otosclerosis
Caucasian 10%
Asian 5%
African descent 1%
Common in the Southern State of Tamil Nadu and North
Eastern part of the countries like Orissa, West Bengal &
Bangladesh

11. • Gender
– Histologic otosclerosis – 1:1 ratio
– Clinical otosclerosis – 2:1 (F:M) and 3:1(if AB Gap >30dB)
• 4:1 (in older age group 60 – 80yr)
• Increase progression during pregnancy (10%-17%)
• Bilaterality more common
• Age
– 15-45yr most comon age range of presentation
– 0.6% of individuals <5 yr old have foci of otosclerosis

12. PATHOPHYSIOLOGY
• An otosclerotic lesion consists of
– Areas of bone resorption
– New bone formation
– Connective tissue stroma
– Vascular proliferation
• Earliest histologic alterations is 'blue mantle'
• Blue mantles are areas of the otic capsule that stain more
basophilic than normal.

13. “Blue mantles of Manasseh”
Resorption of enchondral bone with enlargement of perivascular
spaces followed by deposition by immature (spongy) bone and a lot of
cement substance/connective tissue stroma which stains blue with
haematoxylin –eosin stain.

14. PATHOPHYSIOLOGY
• There is – Resorption of endochondral bone with
– Enlargement of the perivascular spaces followed by
– Deposition by immature (woven) bone & connective tissue
– Active resorption and remodelling occur continuously
– Production of more mature (lamellar) bone
– Proliferation of blood vessels in active otosclerotic foci

15. • Otosclerotic foci
– Contain a stroma made up of fibroblasts and histiocytes.
– Absence of acute inflammatory cells or PMN leukocytes.
– Focus is larger in volume than the bone, thus otosclerosis
causes thickening of the structures affected.
– Active or 'spongiotic' characterized by areas of increased
cellularity and vascularity as well as bone resorption and
new bone formation
– Inactive 'sclerotic' focus consisting of dense mineralized
bone.

16. • Expansion of otosclerotic foci can obliterate the oval and
round windows.
• Invasion of the labyrinthine spaces is rare and occurs only in
the most active lesions.
• Lumens of the IAC or facial canals are not invaded, even in the
most severe cases.

17. • Temporal bone section from a 68-year-old man showing
– Focus of active otosclerosis that has reached the endosteum of cochlea.
– There is atrophy and hyalinization of the spiral ligament.
– The organ of Corti is intact
– The stria vascularis appears normal.

18. • Temporal bone section in - 85yr old man with otosclerosis
– Focus of otosclerosis ant. to the OW, contains many vascular channels.
– Ankylosis of stapes footplate (ant. part) and has also pushed the footplate
posteriorly, resulting in narrowing of the posterior stapedio vestibular joint.
– The otosclerotic focus has also reached the endosteum of the basal turn of
the cochlea. Note that the sensory and neural elements of the cochlea are
intact, including the organ of Corti, stria vascularis and spiral ganglion cells.

19. • Distribution:
– Usually b/l – 70-90%
– Ant.to oval window – 80-95%
– Round window niche – 30%
– Medial wall of Cochlear labyrinth – 15%
– Foot plate – 12%
– Post.to oval window – 5-10%
– Other less frequent sites
• Walls of IAC
• Around vestibular and cochlear aqueducts
• Around SCC, malleus and incus

20. Pathology of CHL
• Involvement of the stapes – CHL - 5 to 60 dB.
• Expansion of focus
– Ant.to oval window – fibrous fixation of FP – upto 30dB
– Bony fixation of FP – 30 – 40dB
– Diffuse bony ankylosis of annular lig – CHL - >40dB

21. • Relationship b/w specific histologic changes at the stapes
footplate and magnitude of the air-bone gap
– CHL correlated highly with narrowing and impairment of
the annular ligament, especially at the posterior
stapediovestibular joint space
– Size of AB Gap determined by extent and degree of
narrowing

22. Pathology of SNHL
• Occurs when the focus reaches endosteum of cochlea
• Atrophy of spiral lig
with impairment of
fibrocytes and
replacement by
eosinophils –
hyalinisation of SL

23. • Fibrocytes – coupled, connected by gap jn, forms channel for
flow of ions and metabolites
– Contain enzymes, protein, cytokines are critical for
maintaining metabolic and ionic homeostasis of cochlea
• Cytokines released by the remodelling bone has reached
the ligament diffuse into the spiral ligament upset
the normal state of cytokine control In turn, this would
disrupt fluid and ion homeostasis within the cochlea lead
to a SNHL

24. Pathology of vestibular symptoms
• Degeneration of Scarpa's ganglion resulted from
– Soluble toxic substances liberated by otosclerotic bone (or)
– Changes in biochemistry of the inner ear fluids (or) both
• The incidence of vestibular symptoms correlated with the
degree of SNHL

25. Causes
• Genetic – AD, with incomplete penetration
– COL A1 gene
• Measles – measles RNA – Foot plate specimen
– Elevated levels of antimeasle antibodies in perilymph
– Incidence reduced after vaccine
• Pregnancy and lactation

26. Clinical presentation
• Hearing loss of gradual onset at 15 - 45 years
• Family history
• Slowly progressive course
• Usually bilateral
• Accelerates with pregnancy, estrogen therapy
• Tinnitus
• Paracusis Willisii
• Change of the speech pattern
• Vestibular symptoms

27. EXAMINATION
• Otomicroscopy
– Intact TM
– Schwartze’s sign
• Red vascular blush
seen
• Excessive vascularity
within the mucosa over
an otosclerotic focus
near the oval window
and promontory
– Imp: Can be a source of
unwanted bleeding during
stapes surgery.

28. Hearing evaluation
• Tuning fork test
• Tympanometry
• Acoustic Reflexes
• Pure tone audiogram

29. Tympanogram

30. Acoustic reflex
• Very sensitive
• Absent reflex
• Precedes hearing loss

31. Carhart’s notch
• Decrease in bone
conduction thresholds
• 05 dB at 500 Hz
• 15 dB at 1000 Hz
• 20 dB at 2000 Hz
• 05 dB at 4000 Hz
• Reverses following
successful surgery

32. Imaging
• CT
• MRI

33. CT
Axial cuts
Patient position – canthomeatal line perpendicular
to the table top
1 mm cuts
Top of sup. SCC to bottom of the cochlea
Coronal
Patient position – supine w/ head overextended
face turned 20 degrees ipsilateral

34. • Ref – bela Purohit, Robert Hermans, katya Op de beeck Imaging in
otosclerosis: A pectorial review insights imaging 2014 5:245- 252

37. CT grading system (Symons and Fanning):
• Grade 1
– Solely fenestral, either spongiotic or sclerotic lesions, evident as a
thickened stapes footplate, and decalcified, narrowed or enlarged
round or oval windows
• Grade 2
– Patchy localized cochlear disease (with or without fenestral
involvement)
• Grade 2A: basal cochlear turn involvement
• Grade 2B: middle / apical turns involvement
• Grade 2C: both the basal turn and the middle / apical turns
involvement
• Grade 3
– Diffuse confluent cochlear involvement of the otic capsule (with or
without fenestral involvement)

38. Axial CT images of the petrous bone in patients with otosclerosis.
. Lee TC1, Aviv RI, Chen JM, Nedzelski JM, Fox AJ, Symons SP. CT grading
of otosclerosis 2009 Aug;30(7):1435-9.

39. Pisa sign
• Evaluate the obliquity of stapes towards promontory and the
torsional effect of otosclerosis on the stapes and rest of the
ossicular chain by radiological imaging
• Torsional stresses on the stapes pulling the incus down is
believed to be responsible for Malleoincudal dislocation

40. Pisa sign
• Length
– A straight line was drawn to measure distance b/w the mid
horizontal segment of facial nerve and stapes head in
coronal sections
• Angle
– The angle measured between two lines, one from the oval
window to head of stapes and second line from the
promontory to stapes head

41. • Illustration showing the increase in length
from facial nerve to stapes head due to
obliquity of stapes in otosclerosis
• Illustration showing change in
angle due to obliquity of stapes
in otosclerosis (dotted line).
* Veluswamy Anand, H. N. Udayabhanu, B. Siva Subramaniam: Obliquity of the Stapes in
Otosclerosis: A New Radiological Sign Int Arch Otorhinolaryngoly :2016;20:94–98.
LENGTH ANGLE

42. Length in otosclerotic pt - 2.49 mm +/- 0.24 mm SD
in non-otosclerotic pt - 1.46 mm +/- 0.16 mm SD
Mean angle In otosclerosis pts - 64.55° +/- 7.19° SD
in non-otosclerotic pts - 99.70° +/- 4° SD.
showing length and angle
measured in Otosclerotic patient.
length measured in non-otosclerotic
patient
angle measured in non-otosclerotic
patient..

43. • MRI
– MRI has a limited role.
– Lesions in the lateral wall of the labyrinth
– In retro-fenestral otosclerosis, pericochlear and
perilabyrinthine soft tissue intensity signal on T1 with
contrast enhancement may be demonstrated.

44. Treatment
• Observation
• Hearing aid
• Medical treatment
• Surgical treatment

45. Indications of observation
• Unilateral mild CHL
• Young age
• Refusing surgery

46. Hearing aid
• As a primary treatment in CHL
• In combination with surgery
– Useful in far advanced otosclerosis
– Avoid need for CI
• Post-stapedectomy rehabilitation with hearing aids it is likely
to be the sensorineural rather than CHL
• As a rescue treatment many years after surgery
• BAHA – benefit – do not produce risk of dead ear
– Only hearing ear with otosclerosis
– Post fenestration cavity

47. Medical management
• Aim
– Stabilize the disease by reduction of the osteoclastic bone
resorption and increase osteoblastic bone formation
• Indications
– Cochlear otosclerosis
– Patients with confirmed otosclerosis but having
progressive SNHL disproportionate to age

48. • Drug
– Sodium fluoride: 8mg TID, until hearing loss stabilizes.
– Bisphosphonates eg: itodronate
• Contraindications
– Chronic nephritis
– Rheumatoid arthritis
– Pregnancy and lactation
– Children

49. • Sodium floride
• Idea comes from high incidence in low-fluoride areas
– Antienzymatic activity against proteolytic enzymes
– Reduction of bone resorption
– Changing otospongiotic active lesions to more dense
inactive lesions
– Increase of new bone formation
• The adverse reactions include synovitis, plantar faciitis, peptic
ulcer, anemia, and increased skeletal fragility

50. SURGICAL TREATMENT
• Patient selection
– Socially unacceptable conductive or mixed hearing loss
– Good speech discrimination
– Age
– Lifestyle and occupation
• Flying restrictions – 01 – 24 wk
• Scuba diving restriction - 35% recommended– 01 – 6 months
- >50% recommended - permanent
• Post op test – apply 400mm of H2O – nystagmus
– A-B gap > 20dB

51. • Absolute contraindication of surgery
– The only functioning ear
– Pregnancy
– Active middle or external ear disease
• Other contraindications
– Patients experience frequent changes in barometric
pressure
– Endolymphatic hydrops (constraints for sx – 35dBHL at
500Hz & no high frequency loss)
– TM perforation

52. Stapes surgery
• Stapedotomy
• Stapedectomy
• Anterior crurotomy

53. APPROACH
Permeatal Endaural

55. Stapedotomy
• Equal or slightly better results with less vestibulo cochlear side
effects

56. Stapedotomy

57. Stapes prostheses. (A) Teflon piston. (B) Platinum–teflon
piston. (C) Titanium–teflon piston
Titanium soft clip pistons

58. Laser stapedotomy

59. Lasers in stapes surgery
• Reduce the incidence of intraoperative floating footplate and
incus dislocation.
• As effective as traditional techniques for closure of the air-
bone gap.
• Lasers – Argon
– KTP
– CO2 – decreased inner ear trauma,
• Risk of perilymph heating - reduced by pulsating the
beam, (micropips)
– Er:YAG laser – limited thermal effect
• The newly introduced CO2 laser hand piece is safe and
effective and laser of choice for stapedotomy.

60. Stapedectomy
• The operation is unavoidable in
– Comminuted fracture of the footplate
– Floating footplate
– Revision surgery
• More traumatic to the inner ear
– Increased post-op vestibular symptoms
– Higher incidence of postoperative SNHL

61. Stapedectomy

62. STAMP ( stapedotomy minus prosthesis)
• By Silverstein in 1998
• Lesion Ant.part of footplate
• Preservation of the stapedius tendon
– Better speech discrimination in noisy environments
– Increased tolerance for high-amplitude sounds
• No prosthesis complications

63. STAMP ( anterior crurotomy)

64. Outcome of stapes surgery
• After stapes surgery, the biologically remodeled incus would
revert back to its original position due to the absence of
torsional forces of otosclerosis and subsequent pull by the
superior incudal ligament
• Closure of A-B gap <10 dB in > 90% cases
• Persistent benefit > 90% cases
• Profound postoperative SNHL < 1% cases.

65. OPERATIVE PROBLEMS
• Tear in TM flap
– Tragal perichondrium/ fascia graft
• Subluxation/ dislocation of incus

66. Dehiscent / over hanging facial nerve
• 0.5 %
• Stapedotomy is usually possible
• FN abuts promontory inf to OW surgery should not be
completed
• Sx completed by drilling fenestra inf. Part of annular lig.
• Prosthesis must be longer

67. Bleeding
• Mucosal trauma – most common cause
• Active phase – preoperative sodium
fluoride may help
• Persistent stapedial artery – bipolar
cautery or small fenestra stapedotomy in
post segment after mobilizing the artery

68. Obliterative or solid footplate
• Incidence 7-11%
• Solid > obliterated
• Drill out 0.7mm diamond burr
• More chance of post op SNHL
• More chance of reclosure
• Post op sodium fluoride may help

69. Floating footplate
• May be avoided if control holes
are used or by using laser
fenestration
• Extraction is difficult, by
needles/hooks with hole
inferior to the oval window
• Another method is removal
after breaking into several
pieces – submerged footplate
• Fenestration before removal of
suprastructure

70. Floating footplate
• Laser fenestration
• Tissue graft (vein) then
prosthesis

71. Incus problems
• Congenital anomalies – short or malformed long process
• Fixation – congenital, developmental, inflammatory
• Necrosis – due to pressure necrosis and insufficient blood
supply
• Dislocation or subluxation
– Remove incus and use malleus attachment prosthesis

72. Malleus ankylosis
• About 1% cases
• May be congenital or acquired (TS)
• Causes about 15-20 dB CHL
• Occurs in later life, Carhart notch, fixed manubrium
• Gentle tap over malleus neck may suffice
• Remove malleus head and the incus and use TORP

73. CSF Gusher
• One of the most dreaded intraoperative complication
• Incidence – 0.03%
• Most reported cases - congenital foot plate fixation
– Widened cochlear aqueduct
– Defect in fundus of IAM

74. CSF Gusher
• Management –
– Immediate head elevation
– Small fenestra stapedotomy
– Placement of large tissue graft prior to prosthesis insertion

75. Perilymph fistula
• Primary - present at the time of surgery
• Secondary – fistula occurs following initial sealing
• Occurs in 9-10% of failed surgery
• Hearing loss, tinnitus, vertigo, disequilibrium
• Several factors contribute –
– Too long prosthesis
– Gelfoam seal of oval window
• Avoid nose blowing, flying, diving, & lifting heavy objects
postoperatively

76. COMPLICATIONS
• TM Perforation
• Chorda tympani injury

77. Reparative granuloma
• Granulation tissue formation around the prosthesis and incus
• 1-5%
• Gradual deterioration 5-15 days postoperatively
• Vertigo, tinnitus and deafness
• Otoscopy: reddish discoloration of the posterosuperior TM
• Treatment – immediate exploration and excision

78. SNHL
• 0.6-3% mostly 1st yr of surgery
• Serous labyrinthitis - high frequency hearing loss, vertigo
• Surgical trauma – excessive drilling - permanent hearing loss
• Perilymph leak
• Degeneration of cochlear component
• Reduced blood supply to cochlea
• Acoustic trauma

79. Persistence or recurrence of CHL
• Prosthesis malfunction – short prosthesis, loose wire
syndrome
• Fibrous adhesion, high membrane formation in oval window
• Incus erosion
• Missed pathology: e.g. malleus fixation, round window
otosclerosis
• Otosclerosis regrowth

80. Incus erosion
Missed pathology: e.g. malleus fixation, round
window otosclerosis , Otosclerosis regrowth
Fibrous adhesion, high membrane
formation in oval window
Prosthesis malfunction

81. Revision stapedectomy
• Delayed/immediate post op CHL
• Symptoms of PLF
• Reperative granuloma
• Less Successful results than first operation
• LA, Laser is beneficial
• 8 to 33% with worsening
• SNHL in 3 to 20%

82. Surgical treatment of bilateral otosclerosis
• Poorer ear 1st with +ve results then 2nd
• Gap – 1-180m (median 24m)

83. Cochlear implantation
• Indication – profound b/l SNHL
• In far advanced otosclerosis after failed surgery
• No improvement with hearing aids

84. Thank you