Ossicular prosthesisOssicular prosthesis

Presenter- Dr.Abhineet jainPresenter- Dr.Abhineet jain

Moderator –Dr .Manjunath D.Moderator –Dr .Manjunath D.

IntroductionIntroductionEtiology of ossicular disruption

EtiologyEtiology Discontinuity

– Trauma– Erosion by chronic otitis media/ cholesteatoma (most

common)• Eroded incudostapedial joint (80% of patients)• Absent incus• Absent incus and stapes superstructure

Fixation– Malleus head ankylosis (idiopathic)– Ossicular tympanosclerosis– Scar bands in chronic otitis media

Nodol and Schuknecht modification of Nodol and Schuknecht modification of the wullstein classificationthe wullstein classification

Type I – myringoplasty (intact and mobile ossicular chain)Type II – use of prosthesis to connect a discontinuity between the long process of incus and stapes head.Type III – subdivided into three categoriesType III stapes columella – placement of TM graft on to the stapes headType III minor columella – strut from stapes head to manubrium/ TM.Type III major columella – strut from stapes foot plate to manubrium / TM.

Mirko toss classificationMirko toss classification Type I – Myringoplasty (intact ossicula chain) Type II – Ossiculoplasty in defective ossicular chain but

with Stapes present. Includes 1. interposition technique.2.transposition technique3.pexis

Type III- ossiculoplasty in cases with absent or severely defective, stapedial arch, if columella techniques are used.

Type IV – no ossiculoplasty .includes cavum minor technique or sound protection technique.

Type VA – fenestration of the lateral semicircular canal in cases with no ossicles and fixed foot plate..

Type VB – platenectomy in cases with fixed footplate

Preoperative AssessmentPreoperative Assessment The goal of ossicular chain reconstruction is better

hearing, most typically for conversational speech.

Bringing the operative ear to within 15 dB of the contralateral ear will enhance binaural input to auditory centers; A patient's perceived hearing improvement is best when the hearing level of the poorer-hearing ear is raised to a level close to that of the better-hearing ear.

In patients with severe mixed hearing loss, ossicular reconstruction can be considered, because it may enhance the use of amplification.

ContraindicationsContraindicationsAcute infection of the ear is the only true

contraindication. Acute infection will most likely result in

poor healing, prosthesis extrusion, or both. Relative contraindications include

persistent middle ear mucosal disease, tympanic membrane perforation, and repeated unsuccessful use of the same or similar prostheses.

PROSTHESIS PROSTHESIS MATERIALSMATERIALS

Autogenous incusCortical boneAllogenous incusTragal cartilageConchal cartilageBiocompatible materials

Incus prosthesisIncus prosthesisAutogenous incus is best even in cases of

cholesteatoma provided no body erosion.Minimal risk of resorption and extrusion.Shape of incus prosthesis varies with

distance between stapes head and handle.Should it have an acetabulum ,or in contact

with drum or malleus.Size should be checked repeatedly during

drilling.

Bone prosthesisBone prosthesis Cortical bone is

chiseled off. L-shape columella

made out of it is thin with sharp edges.

Allogenous cortical bone from tibia treated with chloroform-methanol and freeze dried.

Cartilage prosthesisCartilage prosthesis Easy to harvest and cut. Very less fixation to

surrounding. Perichondrium preserve

vascularity. Thin in one layer to bridge

gap up to graft. After years it become

fibrotic and sound transmission decreases.

Biocompatible materialsBiocompatible materialsPolyehylene,TeflonPorous plasticCeramicsGlass ionomer cementMetals

PORPPORPPartial replacement prosthesis is that is

used to bridge the gap between TM or handle of malleus and stapes head.such condition is usually created after incus and incudo stapedial joint erosion.

It has a tubular shaft and a plateform of smooth edges and variable thickness.

Polyehylne,teflonPolyehylne,teflon1st prosthesis material used.Extrusion rates were as high as 30-50% in

1st year.Due to stiffness of materials, head of stapes,

ant. Crura of stapes get resorbed after long term contact.

Porous plasticPorous plasticIt includes-porous

polyethylene,proplast,teflon plus vitrified carbon,plasti- pore,polycel.

Porous nature enables them in principle to be infilterated by living tissue, leading to effective integration and biocompatibility.

Cartilage covering the plateform may or may not be used.

CeramicsCeramicsA non organic crystalline material with

good biocompatibility.Types-bio inert ceramic made up of

aluminum dioxide.Attachement to head of stapes can be

improved by drilling groove in to shaft to fit over stapes tendon and large hole in to shaft to allow in growth of fibrous tissue.

Bioactive ceramicsBioactive ceramicsIt includes glass ceramics and calcium

phosphate ceramics.Glass ceramics-it is silicon

oxide,ex.BIOGLASS, CERAVITAL.Ceravital-develops an osteogenic surface

reaction after bone paste over plateform, favourable for fixation.CARTILAGE interposition is CONTRAINDICATED.

Calcium phosphate Calcium phosphate ceramicsceramics

Calcium phosphate,tricalcium phosphates,hydroxyapatite.

HYDROXYAPATITE-integrates perfectely with surrounding bone and is IDEAL for middle ear reconstruction.

DENSE form-for ossiculoplasty .MACROPORE form-for cavity

obliteration, as it is filled with fibrous tissue and replaced by bone in 3 months

Glass ionomer cementGlass ionomer cementA glass powder with a polyacrylic acid.To prepare, acid is forced in to glass

powder filled capsule and mixwd for 15 sec.this paste is workable for 5 min,in this time it is transferred to site of surgery where it binds to bone.

The prosthesis has good biocompatibility ,is bioinert and no biodegradability.

MetalsMetalsGeralsch wire basket prosthesis-stainless

steel wire.Resembles physiological condition with a

large area laterally at drum and small at stapes with good sound transmission.

Gold prosthesisGold prosthesisBiocompatible ,easy to shape.Major problem is softness of gold that

compromises rigidity, precise shape and size.

BELL prosthesis as PORP.ANTENNA prosthesis as TORP.

TitaniumTitaniumAs far back as 1993, a group of surgeons

designed the total (Arial) prosthesis and the partial (Bell) prosthesis.

These are available commercially from Kurz.

In 1996, Spiggle and Theis introduced new titanium prostheses that can be trimmed intraoperatively to the appropriate length

Properties of titanium make it possible to

manufacture an extremely fine and light prosthesis with rigidity.

Differential processing of material surfaces triggers various tissue reactions.rough milled surface are most appropiate in areas of contact of cartilage or stapes.

Smoother the surface,less connective tissue reaction.

TORPTORPTotal ossicular replacement prosthesis used

as columellae to bridge the gap between mobile footplate and TM or malleus handle.

As used in type 3 tympanoplasty,the outcome and long term prognosis with columella is poorer as it is associated with more pronounced disease and mastoidectomy

The risk of fixation is more.

Polyethylene,teflonPolyethylene,teflon

Columella with tube and a small plateform.

Very high extrusion rates.

Porous plasticPorous plastic Columella with tube

and broad plateform. Shaft may be of teflon. Cartilage –

perichondrium graft may be used to cover the plateform.

Polycel columellaPolycel columella Malleable TORP

containing stainless steel wire.

Shaft is thin ,can be bent in various planes at various levels,trimmed to various length.

Peg TORPPeg TORP Peg top has a peg on

top of plateform to which a cartilage can be mounted.

Peg stem has a peg on distal end of shaft to fit in to stapedotomy,so used in noninfective,intact drum ear with good tubal function.

Ceramic columellaCeramic columella L shaped or angled

with 1-3 groove in the plateform.

Small holes at shaft to fix fibrous tissue.

Head may or may not be covered with cartilage.

Hydroxyapatite columellaHydroxyapatite columella

Metal columellaMetal columella Gold Stainless steel wire

Hybrid prosthesisHybrid prosthesisCombination of various materials to achieve

different properties of shaft and plateform to avoid or reduce the risk of prosthesis fixation,extrusion,stability.

Usind a plasti pore,polycel shaft provide malleability while plateform of hydroxyapatite provides fixation to TM.

Compound columellaCompound columellaPlateform is made up of cartilage or

bone(ossicle,cortical).Relatively large plateform,but functinal

efficacy is not sure.Shaet is of teflon,plasti-pore,polycel.

Mechanics of force Mechanics of force transmissiontransmission

Which Prosthesis?Which Prosthesis?An otologic surgeon must choose his

prosthesis based on the best chance of successful hearing restoration and the lowest chance of complications.

Methods of prosthesis preservationMethods of prosthesis preservation

70% ethyl alcohol 0.02% Aqueous Cialit, (Sodium 2-

ethylmercurithiobenzoxazole-carboxylate) 4% Buffered formaldehyde fixation and 0.5% buffered

formaldehyde preservation. 4% Buffered formaldehyde fixation and 0.02% aqueous

Cialit preservation. 0.5% Buffered glutaraldehyde fixation and 0.02% aqueous

Cialit preservation. Freeze-drying and ethylene oxide gas sterilization 4% Buffered formaldehyde fixation followed by freeze

drying and ethylene oxide gas sterilization.

Defining SuccessDefining SuccessAttempts have been made to standardize

reporting 1995 guidelines of the AAO-CHEPre and postoperative air-conduction and

bone-conduction thresholds are measured at 4 designated frequencies (0.5, 1, 2, and 3 kHz), then averaged

Success is defined as a mean postoperative air-bone gap of less than 20 dB and is the main outcome considered for this talk

Prognostic FactorsPrognostic FactorsIt is clear that optimal results depend not

only on the qualities of the prosthesis, but also on the environment in which it is placed and the surgical techniques used.

Prognostic FactorsPrognostic Factors Austin (1972) defined four groups in which the

incus had been partially or completely eroded: A, malleus handle present, stapes superstructure

present (60% occurrence) B, malleus handle present, stapes superstructure

absent (23%) C, malleus handle absent, stapes superstructure

present (8%) D, malleus handle absent, stapes superstructure

absent (8%)

Prognostic FactorsPrognostic Factors Kartush (1994) proposed a scoring system called

the middle ear risk index (MERI) to form an index score to determine the probability of success in hearing restoration surgery.

MERI is used to describe the preoperative middle ear environment at the time of ossiculoplasty

It incorporates different classifications of middle ear disease and ossicular status, including Austin’s

Prognostic FactorsPrognostic FactorsOssicular chain status, mucosal status,

otorrhea, +/- mastoidectomy, and revision surgery were all significant prognosticators.

Of note, presence of the stapes superstructure was not influential.

Dornhoffer proposed the Ossicular Outcomes Parameters Staging (OOPS)

All studies of prognostic factors identify middle ear mucosal status and presence of malleus handle as important predictors of successful hearing restoration.

Options for POR and TOROptions for POR and TOR With such a variety of options and materials

available for reconstructing the ossicular chain, the otologic surgeon must consider using the method that provides the best hearing result with the least chance of complications.

The ideal study for comparison of techniques would be a single surgeon directly comparing techniques or materials on patients who had been risk stratified by a validated prognostic index, with reporting of complication rates and long-term follow up.

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