otosclerosis

1. OTOSCLEROSIS
Dr. Rajesh Maharjan
ENT 1st year Resident
GMC

2. INTRODUCTION
• Localized hereditary disorder of bone metabolism of
otic capsule enchondral bone that is characterized by
disordered resorption and deposition of bone
• Bone resorption by osteoclasts and new bone
formation by osteoblasts, accompanied by vascular
proliferation and tissue stroma
• New vascular spongy bone formation causes ankylosis

3. Antonio Valsalva
Italian Anatomist
First described
ankylosis of stapes
in 1741

4. Joseph Toynbee
• First described the
condition causing a
hearing loss by fixation of
the stapes in 1860

5. Anton von Tröltsch
• 1869
• Final inactive
sclerotic stage of the
disease, "sclerosis”

6. Adam Politzer
1893
Coined the term
Otosclerosis
in

7. Friedrich Siebenmann
Swiss otolaryngologist
Coined the term
Otospongiosis
in 1912

8. INTRODUCTION

9. EPIDEMIOLOGY
• Exact etiology is unknown (? Viral)
• Paget’s disease
• Measles virus protein, low level of anti measles IgG
• Autoimmune
• Humoral mediated
• Type II and IX collagen

10. EPIDEMIOLOGY
• Autosomal dominant: variable penetrance
• Race: common in white races & Indians
• Female : Male = 2 : 1
• Age: Common in 20 - 30 years
• Hormonal influence: es in pregnancy, menopause,
stress (trauma, surgery)

11. TYPES
I. Clinical otosclerosis
• Stapes
• Stapediovestibular joint or round window membrane
II. Cochlear otosclerosis
• Cochlear endosteum without affecting the stapes or the
stapediovestibular joint
III. Histological otosclerosis
• Histopathological lesions
• Do not affect the stapes, stapediovestibular joint or cochlear
endosteum
• Asymptomatic

12. HISOTPATHOLOGY
• Two cytokines,
• Osteoprotegerin (OPG)
• Potent inhibitor of osteoclast activation and maturation
• RANKL (receptor activator nuclear-kb ligand)
• Osteoclast activator
• Breakage in signaling pathway between two cytokines

13. LIGHT AND ELECTRON MICROSCOPY
• Earliest indication
• Resorption of enchondral bone around blood vessels
• Enlargement of perivascular spaces followed by deposition of immature
(woven) bone
• Active otosclerotic foci
• Increased vascularity and increased bone turnover
• Inactive (sclerotic) foci
• Dense mineralized bone
• The connective tissue stroma in the foci consists
• Fibroblasts and osteocytes
• Complete absence of acute inflammatory cells

14. ORIGIN AND SITES
• Wall anterior to the oval window > round window
niche > cochlear apex
• Less frequent sites
• Posterior to the oval window
• The internal auditory canal
• Around the cochlear duct and the semicircular canals
• Middle ear ossicles
• Labyrinthine spaces and the vestibular aqueduct

15. CAVITATING OTOSCLEROSIS
• Large cavities may form within otosclerotic foci
• If contact with endosteum of scala tympani
• 3rd window
• Persistence of air bone gap following stapedectomy
• Communicate with the CSF space in the internal
auditory canal
• Result in gushers during cochlear implantation

16. TYPES OF STAPEDIAL OTOSCLEROSIS
1. Anterior focus (commonest): 2 mm anterior to oval Window
2. Posterior focus: 2 mm behind oval window
3. Circumferential: involves footplate margin only

17. Types of Stapedial Otosclerosis
4. Biscuit type: footplate involved, margin is free
5. Obliterative: obliterates oval window completely

18. Symptoms of Otosclerosis
• Hearing loss: Bilateral, slowly progressive
• Conductive: stapedial otosclerosis
• Sensori-neural: cochlear otosclerosis  hyalinization and atrophy of spiral
ligament
• Mixed: stapedial + cochlear otosclerosis
• Vestibular symptoms
• Vestibular ganglion degeneration
• Asso. Meniere’s disease
• Vestibular aqueduct filled with active otosclerotic foci

19. Symptoms of Otosclerosis
3. Paracusis Willis: Better hearing in noisy surroundings (people
increase their voice intensity & pt’s speech discrimination
becomes better).

21. DIAGNOSIS
• Otoscopy
• Normal, mobile tympanic
membrane
• A red blush of the
tympanic membrane over
the promontory ‘Flamingo
flush’ or Schwartz sign

22. TUNING FORK TESTS
Rinne Weber A.B.C.
Stapedial Negative
(BC > AC)
Lateralizes to
diseased ear
Normal
Cochlear Positive
(AC > BC)
Lateralizes to
Better ear
Decreased
Mixed Negative
(BC > AC)
Lateralizes to
Better ear
Decreased

23. GELLE & BING TESTS
Vibrating tuning fork placed over mastoid & then:
External auditory canal is blocked in Bing test or
E.A.C. pressure ed by Siegalization in Gelle test
Bing Gelle’s
Otosclerosis No change No change
Normal / SNHL Intensity es Intensity es

24. PURE TONE AUDIOMETRY
• Low frequency
conductive
deafness
• Carhart’s notch in
bone conduction
at 2 KHz
• All CHL,
irrespective
etiology

25. CARHART EFFECT
• Highest for 2 kHz

26. TYMPANOMETRY

27. STAPEDIAL REFLEX

28. RADIOLOGY
• High-resolution CT (HRCT)
• Active otosclerosis as hypodense or lucent areas within the otic capsule,
typically anterior to the oval window

29. SURGICAL DIAGNOSIS
• Middle ear anatomy normal
• Bone around oval window whiter than normal but no
clear junction
• Footplate thicker

30. HISTOLOGICAL DIAGNOSIS
• Only if stapedectomy performed
• Stapedotomy
• Stapes superstructure
• Non otosclerotic bone

31. DIFFERENTIAL DIAGNOSIS
• Otitis Media with Effusion: type B tympanogram
• Adhesive Otitis Media: absence of T.M. mobility
• Tympanosclerosis: white patch on T.M.
• Ossicular discontinuity: type Ad tympanogram
• Congenital ossicular chain fixation: tympanotomy
• Malleus head fixation: tympanotomy

32. MANAGEMENT
• Medical
• Fluoridation of drinking water
• No data till date in support
• Oral Fluoride
• Given in active focus of otospongiosis (Schwartze sign)
• Acts by:
a. Decreases bone resorption
b. Increases bone formation
• 20 mg orally, thrice daily for 3 - 6 months
• S/E arthritis, gastroenteritis, anemia, plantar fascitis
• Bisphonates
• may reduce the deterioration of sensorineural hearing loss over time

33. HEARING AIDS
• Unfit for surgery
• Disadvantage
• Aesthetic concern as patient usually
of young age
• BAHA (Bone Anchored Hearing
Aid)
• An only hearing ear with otosclerosis
• Difficulty using a conventional aid
• Post-fenestration cavity

34. FAR-ADVANCED OTOSCLEROSIS
• Average air-conduction of > 85 db
• Bone conduction immeasurable due to limits of
audiometric equipment
• Distinguish from Pure SNHL
• Timescale of the hearing impairment
• Family history, previous audiograms showing an air–bone gap
• No CT evidence of cochlear otosclerosis
• Managed in 1 of 3 ways
• Stapedectomy and subsequent conventional hearing aids
• Cochlear implantation
• The new direct acoustic cochlear stimulation (DACS) device

35. DIRECT ACOUSTIC COCHLEAR STIMULATION
(DACS)
• The device consists of an active middle ear implant
attached to a stapes prosthesis
• Mixed hearing loss where a successful stapedotomy
alone would not allow the patient to manage without
a hearing aid
• Indications
• Minimum average bone-conduction of over 30 db and with
an additional air–bone gap of over 30 db

36. COCHLEAR IMPLANT
• Patients with FAO or failed stapedotomy may be candidates for
cochlear implantation
• There may be problems in electrode placement due to
otosclerotic ossification of the round window or basal turn of
the cochlear which may necessitate extra drilling

37. SURGERY

38. SURGERY
• 1878
• Transtympanic mobilization and
removal of the stapes
• 1899
• 6th International Otologic
Congress in London
Johannes Kessel

39. SURGERY
• 1956
• Binocular microscope
• Stapedotomy
• Ossicular
reconstruction/teflon piston
• Vein graft
John Shea

40. INDICATIONS
• Hearing threshold for air conduction 30 dB or more
• Average air bone gap at least 15 dB or more at
frequencies of 250 Hz to 1 kHz
• Negative Rinne at 512 Hz

41. INDICATIONS
• Bilateral involvement
• worse hearing ear/ interval 1 yr
• Symmetric loss
• Patients preference
• Concomitant sensorineural loss is not a
contraindication for surgery

42. CONTRAINDICATIONS
• Only hearing ear
• Infection of external or middle ear
• Pregnancy
• Tympanic membrane perforation

43. FACTORS TO CONSIDER
• Age
• Children
• CT temporal bone
• Congenital Middle/inner ear malformation
• No upper age limit
• Occupations
• Scuba diving, commercial air travellers, parachuting
• Barotrauma
• Tympanometric pressure of 400 mm of H2O, if no nystagmus
• Work in noisy environment
• Ménière’s disease
• Distended saccule close to oval window

44. INFORMED CONSENT
• Description of the procedure and discussion of all
potential risks
• Occupational dependence on taste

45. OPERATIVE NOTE
• Shape and mobility of the incus and malleus
• Presence of otosclerosis
• Fixation of the stapes
• Patency of the round window
• Location of and the bone covering the facial nerve
• Status of the chorda tympani

46. ANESTHESIA
• Local anesthesia
• Time saving
• Intraoperative report of vestibular symptoms
• Prevention of excessive inner ear irritation
• General
• Painless
• Motionless operative field

47. SURGICAL TECHNIQUE

48. POSITIONING
• Supine head tilted 10-15 down
• Head turned to contralateral shoulder
• Tympanic membrane almost horizontal plane

49. EXPOSURE AND EXPLORATION
• Speculum holder attached to the bed or the headrest
• Size
• Too small
• Move against EAC
• Restrict vision and instrumentation
• Too large
• Push soft tissue of EAC medially
• Obstruct view
• Should wedge into lateral aspect of bony canal

50. EXPOSURE AND EXPLORATION
• Local anesthesia 1% lidocaine and 1:100,000
epinephrine
• Minimizes bleeding
• 27 gauge needle 4 quadrants of cartilage EAC
• Lateral to junction
• Bevelled 30-gauge needle into subperiosteal plane at
6 and 12 o’ clock

51. EXPOSURE AND EXPLORATION
• Permeatal incision

52. Tympanomeatal flap raised

53. Posterosuperior annulus

54. CHORDA TYMPANI SEPARATED

55. VISUALIZATION MIDDLE EAR
• Oval window niche
• Pyrimidal eminence
• Tympanic segment of Facial nerve
• Round window
• Operative note
• Malleus incus, stapes fixation, chorda tympani, patency round window

56. EXPOSURE AND EXPLORATION

57. EXPOSURE AND EXPLORATION

58. CRUROTOMY SCISSOR

59. EXPOSURE AND EXPLORATION

60. JOINT KNIFE

61. EXPOSURE AND EXPLORATION

62. FENESTRATION

63. FENESTRATION
• Site
• Middle and inferior 3rd
• Greatest distance from footplate to membranous labyrinth
• Argon vs Carbon dioxide
• Visible light range
• Laser vs Microdrill
• Cut and coagulate
• No pressure and movement
• Less irritation and trauma perilymph

64. PROSTHESIS

65. Piston placed in perforation

66. ALLIGATOR FORCEPS
• Grasped by its loop
• Pace to fenestra and
incus in one movement
• Site
• Narrowest area of incus

67. CRIMPING
• Differential movement
• Delayed failure

68. POSITION
• Perpendicular to footplate
and long axis incus
• Fitting fenestra snugly but
freely moving

69. Tympanomeatal flap put back

70. Stapedotomy Piston

71. STAPEDECTOMY

72. STAPEDECTOY
• Free floating footplate
• Communited fracture footplate
• Inadvertently removed during superstrucure removal
• Revision surgery
• Instrument for fenestration not availabe

73. STAPEDOTOMY VS STAPEDECTOMY
• Hearing difference not significant
• Vestibular symptoms
• Occurrence, duration, and severity

74. Footplate Fenestration

75. Stapes superstructure removed

76. Footplate removal

77. Prosthesis placed over vein graft

78. COMPLICATIONS OF
STAPES SURGERY

79. INTRAOPERATIVE
• Tear tympanomeatal flap
• Perforation TM
• Subluxation Incus
• Facial nerve overhanging
• Obliterative otosclerosis of the oval window
• Otosclerosis involving round window
• Malleus ankylosis
• Perilymph gusher
• Floating and depressed footplate

80. POST OPERATIVE
• Facial palsy
• Chorda tympani dysfunction
• Otitis media
• Vertigo
• Sensorineuronal hearing loss
• Conductive hearing loss
• Malfunctioning prosthesis Malleus fixation OM, DSSC, round window
obliteration

81. REFERENCE
• Scott-Brow’s Otorhinolaryngology, Head and Neck
Surgery, 8th edition
• Glasscock-Shambaugh, Surgery of the ear, 6th edition