Ossicular disorder

a subject that covers most common ossicular disorders with their management.

1. B y : Dr. W udie.M (ORL-HNS R3) Clinical evaluation and management of ossicular disorder 12/5/2020 1

2. outlines Middle ear anatomy & physiology Types of ossicular dysfunction Discontinuity Fixation Clinical evaluation of ossicular function Management refferences 12/5/2020 2

3. Anatomy and physiology of middle ear Middle is air filled space Divided into hypotympanum, mesotympanum , and epitympanum The epitympanum , lies above the level of the malleolar folds. The hypotympanum lie below inferior tympanic sulcus- this space may contain a dehiscent, high-riding jugular bulb or an aberrant carotid artery The mesotympanum is the space just medial to the tympanic membrane, Extends from the eustachian tube opening anteriorly to the facial nerve posteriorly 12/5/2020 3

4. Ossicles Malleus composed of head manubrium, neck , ant. and lateral processes The anterior process is attached to the anterior tympanic spine by the anterior mallelar ligament . Tensor tympani muscle attaches to medial aspect of the neck and manubrium. 12/5/2020 4

5. The incus is the largest of the ossicles , composed of a body and three processes The short process of the incus occupies the incudal fossa, attached by the posterior incudal ligament. Body rest to epitympanuem & articute with head of mallues 12/5/2020 5

6. The stapes is the most medial and smallest of the ossicles , composed of a head ( capitulum ), anterior and posterior crura , and the footplate . The footplate is encircled by the annular ligament, which serves as a “joint,” sealing the footplate in OW Stapedius tendon attach to the superior aspect of the posterior crus, just inferior to the head. 12/5/2020 6

7. Blood supply and innervation Middle ear is supplied by two arteries are the main, ( i) Anterior tympanic branch of maxillary artery which supplies tympanic membrane. (ii) Stylomastoid branch of posterior auricular artery which supplies middle ear and mastoid air cells The main innervation of ME is from the tympanic plexus and Jacobson’s nerve, which receives a major contribution from the glossopharyngeal nerve through the inferior tympanic canaliculus 12/5/2020 7

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9. Physiological gain 12/5/2020 9 There are two basic pathways by which sound is able to stimulate the inner ear Ossicular coupling - transmission of sound pressure through the tympanic membrane and ossicular chain via the oval window . hydraulic lever effect - difference between the surface area of the tympanic membrane relative to that of the oval window (usually a ratio of nearly 21:1 ). Gain of 26 dB malleoincudal lever effect – results from length defference b/n handle of malleus and long process of incus along its angle of rotation . 1.3:1 … it has gain of 2 dB Acoustic coupling

10. 12/5/2020 10 - transmision of sound directley to OW and RW with out involvement of TM and ossicular chain. In the presence of intact ossicular chain and TM , it has less importance. Phase- A sound stimulus to the inner ear is detected as the net difference in sound pressures applied to the round and oval windows that results in movement of intracochlear fluids. If these sound pressures are simultaneously applied to the round and oval windows with equal amplitude and phase, they will counteract each other and no resultant intracochlear fluid displacement will occur

11. Otosclerosis Otosclerosis is a disease of bone that is unique to the otic capsule . It may cause a conductive hearing loss, a mixed conductive- sensorineural hearing loss, or occasionally a purely sensorineural hearing loss It has 2 phase of the disease Active phase ( cxzed by bone resorption )- spongiosis Remisssion phase – characterized by bone deposition (sclerosis) 12/5/2020 11

12. Types of otosclerosis Clinical otosclerosis – the lesion that affects the stapdius , stapidiovestibular joint or round wind and causing CHL Cochlear otosclerosis –the lesion involving cochlear endostium with out affecting stapidius or stapidiovestibuar joint, causing pure SNHL Histologic –histopathology of temporal bone shows otosclerosis but clinically asymptomatic Obliterative -involvement of both oval and round window and most of bony labyrinthine. Results mixed hearing loss Far adevanced otosclerosis - Air or bone conduction , or at best Ac not better than 95 dB and bone conduction at 55-60 dB at 1 frequency only. 12/5/2020 12

13. Epidemiology Most common among Caucasians Although occurring in all age groups, usually presentation is b/n 2 nd to 5 th decades of age F:M 2:1 In 70 % of cases , it’s bilateral 12/5/2020 13

14. Etiology Genetic – autosomal dominant Infection such as measles viral infection Endocrine Onset of hearing loss in otosclerosis may associate pregnancy 12/5/2020 14

15. Clinical presentation History Typically, with otosclerosis , hearing loss is gradual onset and progresses slowly over several years. Disease become apparent in late 10s to 20s of age Most of pts will have CHL with paracusis of Willis phenomena. Unilateral hearing loss may be unoticeble & may have difficulty with direction of sound. Tinnitus is 2 nd most common symptoms 12/5/2020 15

16. Positive family hx with negative history for infections or trauma. Physical examination Otoscopic and microscopic examination – to rule out other possible causes of CHL Schwartze sign - a red blush over the promontory or the area anterior to the oval window. Tuning fork test- with 512 Hz Weber's test lateralize to ear which have more CHL Rehn’s test BC> AC in the presence of 15 to 20 dB CHL with 512 Hz fork 12/5/2020 16

17. Investigations PTA- low frequency CHL with a dip at 2 kHz known as Carhart’s notch. BC at 2kHZ is 15dB if it is greater than 15 dB , there may be cochlear OS. Tympanometry -either normal or depressed (As) Stapiediul reflex- normal in early stage , and can’t be elicited in late stage Speech reception and perception test are often normal unless there is choclear involvement. 12/5/2020 17

18. CT Scan and MRI Not routine workups CT scan is more usefull than MRI in OS evalation CT scan is indicated in the following cases CHL but absent carhart notch Equal ABG all over the frequencies Mixed hearing loss All cases of revision stapes surgery Appears as hypodense area, on CT. it has 90% sensitivity. 12/5/2020 18

19. Management Surgical- indication is CHL with ABG >20 dB stapedioplasty Stapedotomy Stapedectomy – total vs partial Medical Hearing aid 12/5/2020 19

20. Stapes Mobilization ( stapedioplasty ) performed selected cases who has small point of fixation of stapes from OS. using an endoscope and the argon laser potentially avoid the placement of a prosthesis Long term follow up show re fixation of stapes. 12/5/2020 20

21. Anterior crurotomy with partial stapedectomy removal of only the anterior footplate and crus . Done in case of only anterior foot plate fixation helpful in a patient with isolated anterior fixation at the fissula ante fenestram . The footplate is fractured in its mid portion, and only the anterior half is removed A connective tissue graft placed over the exposed area The IS join will remain intact and the stapidial tendon will not cut, It has especial benefit for pts who workin noise env’t . 12/5/2020 21

22. Fenestral stapidotomy after adequate exposure is established, the malleus, incus, and stapes are palpated to ascertain mobility. The distance from the incus to the stapes footplate is measured . The usual distance from the lateral surface of the incus to the footplate is 4.5 mm. Because the piston prosthesis is usually measured from the medial surface of the incus, 0.25 mm is subtracted to allow for this distance (incus = 0.5 mm + extension into vestibule of 0.25) . The most common piston size is 4.25 mm. 12/5/2020 22

23. A 0.7-mm diamond microdrill is used to create the fenestra . Usually there is adequate room between the facial nerve and the crus of the stapes to use the drill on the footplate. Despite this, part of the posterior crura is drilled to warn the patient of the drill noise, Weaken the crura for easy fracture, and, at times, allow better access to the footplate . The laser can be employed to begin the fenestra . If the footplate is thin, the drill may not be needed to complete the opening. 12/5/2020 23

24. The fenestra is created with a light touch of the drill . The diamond is allowed to create the fenestra without applying pressure. Excess pressure may fracture the footplate. When the drill is felt to drop into the vestibule, a perfect 0.7-mm fenestra is completed. The 4.25-mm length, 0.6-mm diameter platinum Teflon ( polytetrafluoroethylene ) prosthesis is placed from the incus to the fenestra . It is crimped firmly on the incus . The incudostapedial joint is separated, and the stapedial tendon is sectioned. 12/5/2020 24

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27. Superstructure of stapes fractured and removed Test to prostesis performed to check position Medial lateral excuresion checked with light manuplation If pt feels vertigo, the prostesis may be too long If pt does not feel, check for anterior posterior excursion & no displacement, then Blood is placed around the prosthesis as a seal in the oval window, and the tympanomeatal flap is returned to its normal position. Minimal packing is required on the flap, a cotton ball is placed in the meatus , and a bandage is applied to the ear 12/5/2020 27

28. stapidectomy Total stapedectomy – is surgical removal of total foot plate of stapes with pick and hook replace it with a vein graft and polyethylene strut. partial stapedectomy, removing only the posterior half of the footplate. The footplate is opened with either picks or a microdril The most common tissue types used for grafting are the dorsal hand vein, tragal perichondrium , or fascia. 12/5/2020 28

29. Post operative care Immediately after surgary the pt head should be elvated to 30 degree for an Hr. In the immediate postoperative period, the patient is asked to avoid lifting and straining for about 1 month. Nose blowing should be discouraged. The patient should also cough or sneeze with the mouth open, to reduce the risk of increased middle ear pressure and displacement of the TM . The patient is kept on dry ear precautions until the TM flap has completely healed. 12/5/2020 29

30. A postoperative audiogram is obtained 2 to 3 months after surgery. In 90 % of cases there will be closure of ABG within 10 dB of the preoperative bone-conduction. About 10% of patients experience either worsening hearing or no improvement About 2% of patients suffer persistent and profound SNHL. 12/5/2020 30

31. Out come small fenestra techniques argue that limited opening of the vestibule lower risk of damage to the inner ear and resultant sensorineural hearing loss The most common cause for failure of stapedectomy has been prosthesis displacement, with or without incus erosion. Other causes of failure are footplate refixation , perilymph fistula. otosclerotic regrowth , and lateralization of the OW membrane 12/5/2020 31

32. Persistent or progressive CHL can follow stapedectomy. Loosening or displacement of the prosthesis, resorption of the incus long process, adhesions around the prosthesis, and further OS lesions can produce postoperative CHL 12/5/2020 32

33. complication Immediate complication Complication occurs intra op Facial nerve injury Vertigo- usually resolves with in short period of time Hearing loss Persistant perilymphatic leakage from OW Change in taste- in 9 % of cases , improve with in 3 to 4 mnths Labrynitis Tympanic menbrane perforation- use paper patch Delayed complications Fistula formation – most common cause is poststapedectomy ( 3 % to 9%),rare in stapedotomy Granuloma Prosthesis dislocation- needs revision surgary 12/5/2020 33

34. Alternative treatment Hearing aid- CHL caused by OS may use hearing aid as alternative for surgical mgt Pts who have mixed HL may need Hearing aid after surgical mngt . Fluoride therapy- NaF Pt with progressive hearing loss may benefit It changes active otospongiotic lesion to more otosclerotic lesion Reduce the progression of hearing loss 8mg po TID until the hearing loss stablized 12/5/2020 34

35. Tympanosclerosis It is a deposition of calcium and accellular hyaline to TM and middle ear cleft. Tympanosclerosis most commonly involves the TM- myringosclerosis . If it has extension to middle ear cleft , it may cause ossicular fixation Fixes stapes in the oval window region, and the incus and malleus in the attic, or fixes both simultaneously 12/5/2020 35

36. Pathogenesis. Tympanosclerosis results as a consequence of recurrent AOM, COM , or tympanostomy -tube placement . The exact pathogenesis of tympanosclerosis remains unclear . One possible mechanism is degeneration of fibroblasts which are known to accumulate in these plaques progressively 12/5/2020 36

37. cytosolic matrix vesicles rich in calcium, phosphate, and alkaline phosphatase that eventually merge with the cell membrane and are released extracellularly upon fibroblast-cell death Another possible mechanism is that of dystrophic calcification of degenerated collagen fibers after an infectious or inflammatory insult 12/5/2020 37

38. Diagnosis Usually it’s asymptomatic and incidental finding horseshoe-shaped white plaque over TM If there is ossicular chain involvement, will have significant CHL Management Tympanoplasty with ossiculoplasty 12/5/2020 38

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40. Ossicular chain discontinuity disorder 12/5/2020 40

41. Ossicular trauma Most ossicular injuries are dislocation Dislocation of incuse being the most frequent dislocation Incudo stapidial joint dislocation with minimal incus displacement or complete separation may occur. Ossicular fracture are much less frequent. If it occurs the long process of ossicle is commonest part. Isolated fructure of stapial foot plate is very rare and almost always associated with penetrating trauma. 12/5/2020 41

42. Mechanism of injury – Skull trauma with or without # of the temporal bone is the main cause About 60% occur with out concomitant TB # Barotrauma to middle ear Surgical trauma Drill-induced trauma to the incus during tympanomastoid surgery usually causes incudostapedial joint dislocation 12/5/2020 42

43. Evaluation PTA Initial audiometric evaluation should be done as soon as after the injury. If there is CHL at initial evaluation, , Repeat PTA after 3 months CHL in the presence of intact or healed TM and with out any sign of hemotympanum  ossicular chain disruption Ossicular-chain disruption without perforation may result ABG up to 60 dB With perforated TM ABG 40 to 50 dB 12/5/2020 43

44. Tympanometry - helps to identify cases of complete ossicular disruption Discontinuous ossicular chain allows a wide excursion of the tympanic membrane in response to changing ear canal pressure, AD CT scan- 12/5/2020 44

45. Management of ossicular trauma Conservative management surprisingly good hearing recovery may take place with fibrous healing when the incudostapedial joint is disrupted, even if the incus is entirely displaced, a 3-month period is recommended prior to surgical exploration 12/5/2020 45

46. Surgical management Indication for ossicular reconstruction is conductive hearing loss of more than 30 dB that persists for more than 2 months after injury. The most conducive injury for ossicular reconstruction is a dislocation of the incudostapedial joint . In this situation, an Applebaum hydroxyapatite prosthesis is inserted between the long process of the incus and the capitulum of the stapes . Dislocation of the entire incus requires bridging the gap between the stapes suprastructure and the manubrium of the malleus. A sculpted incus interposition graft is preferred. 12/5/2020 46

47. when the stapes suprastructure is fractured but the incus remains connected to the malleus; these patients are good candidates for a laser stapedotomy . 12/5/2020 47

48. Ossicular erosion Chronic otitis media in almost any form can result in the disruption of the integrity of the ossicular chain. Chronic eustachian tube insufficiency and tympanic membrane retraction that results in prolonged contact of the tympanic membrane with the tip of the incus can cause this type of erosion, even without active infection. Cholesteatoma is the most common cause of erosion of the ossicles . 12/5/2020 48

49. It can result Loss of lenticular process with preservation of soft tissue connection Erosion of long process of incuse with stapes suprastructure Incudostapidial erosion with partial or total malleus fixation 12/5/2020 49

50. Ossiculoplasty MATERIALS FOR RECONSTRUCTION The ideal material for ossicular reconstruction should be biologically stable (resistant to resorption and non-reactive), correct mass and stiffness, be easy to handle, and ideally low cost can be broadly divided into autografts , homografts and alloplastic materials 12/5/2020 50

51. Autografts are tissues that are harvested from the same patient on which they are to be used, and can include ossicles , cortical bone and cartilage. Homograft material is derived from human donor tissue. A wide choice of pre-prepared graft material is available with options including cortical bone, cartilage, ossicles , and en bloc ossicular chain with tympanic membrane attached 12/5/2020 51

52. Alloplastic material solid plastics: polytetrafluoroethylene , polyethylene solid metals: stainless steel, gold, titanium porous sponge-like plastics: ProplastR , Plasti -Pore ceramics: aluminium oxide, hydroxyapatite . PORP = partial ossicular replacement prosthesis. Generally used to mean a prosthesis that is designed for situations with an intact stapes superstructure. TORP = total ossicular replacement prosthesis. For use in situations where there is no stapes superstructure and the prosthesis restores a connection with the stapes footplate. 12/5/2020 52

53. A major decision to be made during surgery for chronic otitis media (especially for cholesteatoma ) is whether to perform ossiculoplasty at the time of the cholesteatoma excision or to perform ossiculoplasty as a planned procedure some months later. Important factors relevant to this decision include the following: Status of the middle ear mucosa, Amount of bleeding, Advisability of reoperation for possible cholesteatoma recurrence, and Middle ear mucosa that is thickened, infected, traumatized, or partially missing is likely to heal with fibrous tissue formation that may displace a perfectly placed prosthesis 12/5/2020 53

54. SURGICAL OPTIONS TO CORRECT SPECIFIC DEFECTS Incus Erosion Erosion of long process of incus is the most frequent ossicular defect There are 2 option to reconstruct incus erosion Reconstruct the incudostapidial joint with type II tympanoplasty If the defect between the incus and stapes is very small, this can be accomplished by wedging a piece of cartilage or bone between the incus and malleus 12/5/2020 54

55. If the defect is large, we can use various prosthesis engaged b/n stapes capitulum and the eroded lentirular process 2. removal of the incus remnant and reconstruction between the stapes and malleus (or tympanic membrane), a type Ill minor columella tympanoplasty . Incus interposition PORP- stapes to malleus 12/5/2020 55

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57. Malleus present, stapes absent 12/5/2020 57 When both the incus and stapes superstructure are absent, common options for reconstruction include a type III major columella mechanism or a type IV tympanoplasty , TORP Stapes foot plate to malleus Stapes foot plate to TM

58. Malleus absent, stapes present 12/5/2020 58 Absence of the malleus handle to be a major independent prognostic factor resulting in poorer hearing outcomes following reconstruction. Reconstructed by using Either by stapes columella or recreate the malleus handle, either with autologous material or with a prosthesis Homograft tympanic membrane with attached malleus handles

59. Malleus and stapes absent 12/5/2020 59 The most challenging ossicular defect and lead to the poorest outcomes reconstruction may be footplate- totympanic membrane , or alternatively a neo–malleus or malleus replacement prosthesis may be used to improve stability

60. Reference 12/5/2020 60 C ummings otolaryngology–head and neck surgery, 5 th edition S cott-brown’s otorhinolaryngology head and neck surgery,8 th edition B allenger’s otorhinolaryngology , head and neck surgery 18 th edition B ailey otorhinolaryngology head and neck surgery, 5 th edition Otosclerosis Diagnosis , Evaluation, Pathology, Surgical Techniques, and Outcomes

61. 12/5/2020 61 Thank you!!