Glossary

The American Academy of Otolaryngology–Head and Neck Surgery's standards for reporting conductive hearing outcomes, specifying the four frequencies (0.5, 1, 2, 3 kHz) for the pure-tone and air–bone-gap average and the use of postoperative bone-conduction thresholds. Adhering to them lets studies of prostheses and techniques be compared on a common footing.

See also: hearing-outcome-guidelinesair-bone-gap-reporting

The reflex contraction of the stapedius muscle to loud sound, measured as a transient change in middle-ear admittance. An absent reflex with a conductive loss supports ossicular fixation or discontinuity, whereas a present reflex with an apparent air–bone gap should raise suspicion of a third-window lesion. It is therefore a key cross-check when interpreting the audiogram.

See also: tympanometry-impedanceaudiologic-discontinuity-vs-fixation

The difference in decibels between air-conduction and bone-conduction thresholds at a given frequency, representing the magnitude of conductive hearing loss available for surgical correction. It is the primary metric for ossicular pathology preoperatively and for judging the success of reconstruction postoperatively, conventionally averaged over 0.5, 1, 2, and 3 (or 4) kHz.

See also: pure-tone-audiometryair-bone-gap-reporting

The reduction of the conductive component after reconstruction, the standard outcome measure in ossiculoplasty. A postoperative gap within 20 dB is the widely accepted threshold of success, with results commonly reported as the proportion of ears achieving a gap of ≤10, ≤20, and ≤30 dB; PORP reconstructions and intact-stapes cases generally close the gap better than TORP cases.

See also: air-bone-gap-reportinghearing-outcome-guidelines

The ring of elastic fibrous tissue that suspends the stapes footplate within the oval window, sealing the vestibule while permitting piston-like motion. Its compliance contributes to the mechanics of sound transfer, and its fixation (as in otosclerosis or tympanosclerosis) produces a conductive loss that ossiculoplasty alone cannot correct.

See also: ossicular-ligaments-jointsstapes-footplate-anatomy

The ratio of the effective vibrating area of the tympanic membrane (about 55 mm²) to that of the stapes footplate (about 3.2 mm²), roughly 17:1. Because force is concentrated from the large drum onto the small footplate, pressure is amplified, contributing the dominant share (around 25 dB) of middle-ear gain. It is the principal reason reconstructions strive to couple a broad drum surface to the oval window.

See also: areal-ratio-mechanismimpedance-matching-principles

A scheme that categorises ossicular defects by which key elements — malleus handle and stapes superstructure — remain present, the variables that most strongly drive prosthesis choice and outcome. Austin's original four groups (based on malleus and stapes status) were expanded by Kartush to add modifiers for malleus head fixation and ossicular fixation, giving a practical map from defect type to reconstruction strategy.

See also: austin-kartush-classificationprosthesis-selection-algorithm

Tissue harvested from the same patient — most often the patient's own incus, sculpted for interposition, or cortical bone — used to rebuild the chain. Autografts are maximally biocompatible and cheap, with negligible extrusion or rejection, but require an available, disease-free ossicle and carry a small risk of harbouring microscopic cholesteatoma if reused from an infected ear.

See also: autograft-incus-interpositionautograft-vs-alloplast

An outcome benchmark holding that surgery is worthwhile if the operated ear reaches a binaurally useful level — broadly, an air-conduction threshold within 30 dB, or within 15 dB of the non-operated ear. It shifts the focus from gap closure on paper to the real-world disability benefit for the patient, complementing audiometric reporting standards.

See also: hearing-outcome-guidelinespatient-reported-outcomes

Richard Bellucci's grading of the ear's inflammatory and drainage status, from a dry, well-aerated ear (group I) through chronic drainage and unfavourable Eustachian-tube or nasopharyngeal conditions (groups III–IV). It stratifies the biological hostility of the ear, complementing structural classifications by predicting graft survival, extrusion risk, and whether staged surgery is wiser.

See also: bellucci-spite-classificationear-environment-risk-scores

A settable paste (glass-ionomer or hydroxyapatite-based) used to bridge short ossicular gaps in situ, most usefully to reconnect an eroded incus long process to the stapes or to refixate an incudostapedial defect. It works best for small, well-supported defects in a dry ear; glass-ionomer formulations fell out of favour after reports of aluminium-related toxicity, leaving HA cements as the safer option.

See also: bone-cement-ossiculoplastybone-cement-indications

The two mastoidectomy philosophies: canal-wall-up preserves the posterior bony canal for a normal anatomy and better hearing platform at the cost of higher residual or recurrent cholesteatoma, whereas canal-wall-down removes the wall to exteriorise disease, trading a mastoid cavity and altered acoustics for safety. The choice shapes the depth and stability available for ossicular reconstruction.

See also: canal-wall-up-vs-downmastoidectomy-for-ocr

A characteristic dip in bone-conduction thresholds maximal at 2 kHz, classically seen in stapes fixation (otosclerosis). It is a mechanical artefact rather than true cochlear loss — the fixed ossicular chain disturbs the bone-conduction response — and bone thresholds typically improve (the notch 'lifts') after the fixation is relieved. Recognising it prevents overestimating sensorineural loss before surgery.

See also: carhart-notchaudiologic-discontinuity-vs-fixation

Reconstruction of the tympanic membrane (and often the scutum) with a plate of tragal or conchal cartilage, frequently with attached perichondrium, to resist retraction in high-risk or revision ears. The cartilage also caps a prosthesis head, distributing load and markedly reducing extrusion, at the cost of a small high-frequency stiffness penalty.

See also: cartilage-shield-techniquecartilage-interposition

An additional source of middle-ear gain proposed by Helmholtz in which the curved, conical shape of the tympanic membrane causes its periphery to move more than the malleus handle, buckling sound energy onto the manubrium. The effect is geometry-dependent and is partly lost when the drum is reconstructed flat, which is one reason graft contour and tension matter acoustically.

See also: sound-transmission-physicscartilage-acoustic-effects

A bioactive glass-ceramic introduced for ossicular reconstruction because it bonds chemically to bone and soft tissue. Although biocompatible at the drum, its tendency to resorb and become incorporated unpredictably over time limited its durability, and it has largely been superseded by hydroxyapatite and titanium.

See also: abandoned-prosthesis-materialsmaterial-science-middle-ear

The branch of the facial nerve carrying taste from the anterior two-thirds of the tongue and parasympathetic secretomotor fibres to the submandibular and sublingual glands. It crosses the middle ear between the malleus handle and the long process of the incus, where it is at risk during tympanomeatal flap elevation and dissection of the incudostapedial region.

See also: facial-nerve-middle-eartympanomeatal-flap

The acoustic principle by which a single rigid strut transmits sound directly from the drum (or malleus) to the oval window or footplate, mimicking the single ossicular column of birds and reptiles. Every PORP and TORP reconstruction is essentially a columella; it sacrifices the lever ratio but can still restore useful hearing if the areal ratio and a mobile footplate are preserved.

See also: porp-design-biomechanicstorp-design-biomechanics

The clinical distinction between an ossicular chain that is broken (discontinuity, typically a large flat-topped low-frequency-predominant gap with hypercompliant tympanometry and absent reflexes) and one that is rigidly fixed (fixation, often a smaller gap, sometimes a Carhart notch, with reduced compliance). The two demand different reconstructions, so separating them on audiometry and impedance testing before surgery is fundamental.

See also: audiologic-discontinuity-vs-fixationtympanometry-impedance

Otologist who proposed classifying ossicular defects by the presence or absence of the malleus handle and stapes superstructure — the two variables most predictive of reconstruction strategy and outcome. His four-group scheme, later modified by Kartush, remains a practical bridge from the operative findings to the choice of prosthesis.

See also: austin-kartush-classification

The portion of the tympanic cavity above the level of the tympanic membrane, containing the malleus head and incus body and bounded laterally by the scutum. It is a common site of cholesteatoma and adhesive disease, and its aeration through the tympanic isthmus is important for chain mobility and graft survival.

See also: tympanic-cavity-boundariesmiddle-ear-aeration-techniques

The triangular space bounded by the facial nerve medially, the chorda tympani laterally, and the incus buttress superiorly. Opening it via posterior tympanotomy provides a canal-wall-up route from the mastoid into the middle ear, giving access to the round window, oval window, and stapes during reconstruction.

See also: facial-nerve-middle-earcanal-wall-up-vs-down

An inert plastic widely used for stapes pistons and some columella prostheses because it is light, easy to shape, and well tolerated by the oval window. It lacks the bone-bonding of bioceramics, so it is favoured where a smooth, low-friction, low-mass strut is wanted rather than tissue integration at the drum.

See also: fluoroplastic-teflon-prosthesesabandoned-prosthesis-materials

German otologist who, contemporaneously with Wüllstein, helped establish microsurgical tympanoplasty and the principles of reconstructing the sound-conducting mechanism with grafts. The Wüllstein–Zöllner era marks the birth of systematic hearing-reconstruction surgery.

See also: wullstein-tympanoplasty-typesreconstruction-techniques-overview

A graphical method that plots each patient's binaural hearing before and after surgery against the better- and worse-ear thresholds, showing at a glance who was helped, unchanged, or harmed in terms of usable binaural hearing. It captures the practical benefit of an intervention better than mean gap figures and is used to audit ossiculoplasty results across a series.

See also: hearing-outcome-guidelinespatient-reported-outcomes

A processed, preserved ossicle (or tympano-ossicular system) taken from a human donor and used to reconstruct the chain. Once popular, homografts have been largely abandoned over concerns about disease transmission (prions and viruses) and limited supply, surviving mainly as a historical and occasional reference point for autograft and alloplastic techniques.

See also: homograft-ossiclesautograft-vs-alloplast

German otologist who in the 1950s, building on the operating microscope and free grafting, systematised reconstructive tympanoplasty into the five-type classification that still organises how surgeons describe middle-ear reconstruction. His work, with Zöllner's, founded modern tympanoplasty and ossiculoplasty.

See also: wullstein-tympanoplasty-types

Thin-section computed tomography that depicts the ossicular chain, scutum, tegmen, facial canal, labyrinthine windows, and the extent of cholesteatoma or erosion in fine bony detail. It is the imaging mainstay for preoperative planning in ossiculoplasty, helping anticipate the defect, identify dangerous anatomy, and decide between staged and single-stage reconstruction.

See also: hrct-temporal-boneimaging-ossicular-erosion

A calcium-phosphate ceramic chemically similar to bone mineral, prized in ossiculoplasty for its excellent biocompatibility and low extrusion rate, especially at the drum interface. It is dense and somewhat heavy and brittle, so it is often used for the prosthesis head or combined with a lighter shaft, marrying a forgiving lateral surface to a more workable column.

See also: hydroxyapatite-prosthesesideal-prosthesis-criteria

The middle ear's central function: overcoming the large mismatch between low-impedance air and high-impedance cochlear fluid so that sound energy is not simply reflected. It is achieved chiefly through the areal ratio of the drum to the oval window and the ossicular lever, together delivering roughly 25–30 dB of gain. Ossiculoplasty aims to restore as much of this transformer action as the remaining structures allow.

See also: impedance-matching-principlesmiddle-ear-mechanics-overview

The middle ossicle, comprising a body that articulates with the malleus head, a short process anchored to the fossa incudis, and a long process that descends to meet the stapes. Its lenticular process forms the incudostapedial joint. The long process has a tenuous mucosal blood supply and is the single most common site of ossicular erosion in chronic ear disease, making it the central problem ossiculoplasty must solve.

See also: incus-anatomy-vulnerabilityossicular-blood-supply

A reconstruction in which the patient's own (or a homograft) incus is sculpted and repositioned to bridge the malleus and stapes, classically when the incus long process is eroded but its body remains usable. The autograft is drilled with a notch or socket to seat on the stapes head and to engage the malleus handle, providing a biocompatible columella with good long-term stability.

See also: incus-interposition-techniqueautograft-incus-interposition

Otologist who refined Austin's defect classification by adding modifiers for malleus head and ossicular fixation, and who developed the weighted Middle Ear Risk Index. His contributions link the structural defect, the hostility of the ear, and the predicted outcome into usable preoperative tools.

See also: austin-kartush-classificationmeri-risk-index

Otologist who advanced cartilage tympanoplasty techniques and, with Gardner, devised the Ossiculoplasty Outcome Parameter Staging (OOPS) index for predicting hearing results. His work ties practical reconstructive technique to evidence-based prognostication.

See also: oops-indexcartilage-shield-technique

The small, disc-shaped tip of the incus long process that articulates with the stapes head to form the incudostapedial joint. Connected to the long process by a thin neck with a precarious blood supply, the lenticular process is frequently the first part of the chain to resorb, producing a discontinuity with an otherwise intact chain.

See also: incus-anatomy-vulnerabilityossicular-ligaments-joints

The most lateral of the three ossicles, the malleus is embedded in the tympanic membrane via its handle (manubrium) and connects to the incus at the incudomallear joint. Its head sits in the epitympanum, suspended by the superior, lateral, and anterior mallear ligaments, and its lateral process raises the visible short process on the drum. Because it is partly protected within the drum and well vascularised, the malleus is the chain element least often eroded by disease.

See also: malleus-detailed-anatomyossicular-chain-anatomy

A prosthesis whose head carries a notch or groove that clips onto the malleus handle, anchoring the device to a stable, well-vascularised structure rather than free under the drum. Engaging the manubrium improves coupling, resists lateralisation and extrusion, and is especially valued in titanium designs.

See also: malleus-notched-prosthesesprosthesis-coupling-stability

The handle of the malleus, firmly attached to the inner fibrous layer of the tympanic membrane from the umbo to the lateral process. Its presence gives the surgeon a stable, well-vascularised anchor point: prostheses are frequently slotted or notched to engage the manubrium, which improves coupling and resists extrusion.

See also: malleus-detailed-anatomymalleus-notched-prostheses

The frequency-dependent way a reconstructed chain transmits sound: added mass (a heavy prosthesis or thick cartilage) preferentially attenuates high frequencies, while excessive stiffness or tension impairs low-frequency transfer. Designing prostheses light and stiff yet appropriately coupled is a balancing act aimed at flattening these losses across the speech range.

See also: prosthesis-mass-stiffnessprosthesis-length-tension

A weighted scoring system (refined from Kartush's work) that sums points for otorrhoea, perforation, cholesteatoma, ossicular status, middle-ear granulation or effusion, and previous surgery to give a single index of how compromised an ear is. Higher MERI scores correlate with worse hearing outcomes and higher complication rates, making it a useful prognostic and counselling tool.

See also: meri-risk-indexprognostic-factors-counseling

A stapes prosthesis whose loop is made of nitinol, a nickel-titanium shape-memory alloy that closes itself around the incus when warmed by body heat or laser, producing a uniform crimp without manual force. Self-crimping aims for consistent, atraumatic coupling and reproducible hearing results compared with hand-crimped wire pistons.

See also: smart-stapes-prosthesis-systemsprosthesis-coupling-stability

The mechanical advantage produced because the malleus handle is longer than the incus long process, so the chain acts as a lever pivoting about the axis through the anterior mallear and posterior incudal ligaments. The lever ratio of roughly 1.3:1 adds a few decibels of gain. Restoring or preserving this geometry is a secondary but real goal of anatomical reconstruction.

See also: ossicular-lever-mechanismimpedance-matching-principles

Dornhoffer and Gardner's prognostic index that scores four intraoperative and clinical factors — ossicular status, middle-ear mucosa/effusion, drainage, and prior surgery (with a point for canal-wall-down or smoking in some versions) — to predict the probability of achieving an air–bone gap within 20 dB. It distils the most outcome-relevant variables into a number that guides expectations and surgical choices.

See also: oops-indexhearing-outcome-guidelines

The membrane-covered opening between the middle ear and the vestibule, occupied by the stapes footplate and sealed by the annular ligament. It is the point at which ossicular vibration is delivered to perilymph; its area (roughly 3.2 mm²) relative to the tympanic membrane underlies the areal-ratio component of impedance matching.

See also: stapes-footplate-anatomyareal-ratio-mechanism

The paradoxical situation in which the postoperative air-conduction threshold is better than the preoperative bone-conduction threshold, giving an apparently negative air–bone gap. It usually reflects relief of a mechanical bone-conduction artefact (such as the Carhart notch lifting after stapes fixation is relieved) rather than a genuine improvement in cochlear function.

See also: carhart-notchaudiometric-outcome-pitfalls

A prosthesis that bridges the tympanic membrane or malleus handle to the head of an intact, mobile stapes, used when the stapes superstructure is present but the incus (or its long process) is lost. By coupling the drum to a stable stapes it restores a columella across a short gap and generally yields better and more reliable hearing than a total prosthesis.

See also: porp-design-biomechanicsstapes-present-porp-technique

A porous high-density polyethylene used for early PORP and TORP designs (e.g. Plastipore, Polycel) whose pores were intended to allow tissue ingrowth. Its relatively high extrusion rate, particularly without a cartilage interposition, drove the shift toward titanium and hydroxyapatite, and it is now largely of historical interest.

See also: abandoned-prosthesis-materialsfluoroplastic-teflon-prostheses

A worsening of bone-conduction thresholds after surgery, the most feared complication of ossiculoplasty because it is usually irreversible. It can result from acoustic or mechanical trauma to the stapes and inner ear during manipulation, an over-long prosthesis loading the footplate, or drill noise, and its avoidance underlies the gentle, footplate-respecting handling emphasised in technique.

See also: sensorineural-hearing-loss-riskcomplication-avoidance-principles

Migration and eventual expulsion of a prosthesis through the tympanic membrane, the commonest mechanical failure of alloplastic ossiculoplasty. Risk rises with bare high-density polyethylene heads, lateral malposition, tension, and poor Eustachian-tube function, and is reduced substantially by interposing cartilage between the prosthesis head and the drum.

See also: prosthesis-extrusionprosthesis-displacement

The matching of a prosthesis to the gap it bridges so that the chain is neither slack nor over-tensioned: too short and the device decouples or migrates, too long and it stiffens the system, distends the drum, and can subluxate the stapes. Correct length-tension is set intraoperatively and is one of the strongest technical determinants of the final air–bone gap.

See also: prosthesis-length-tensionprosthesis-coupling-stability

The core hearing test plotting air- and bone-conduction thresholds across frequencies to quantify the type and degree of hearing loss. The pure-tone average over the speech frequencies, the size and shape of the air–bone gap, and the bone-conduction reserve together define the conductive component a reconstruction can recover and the cochlear function that caps the result.

See also: pure-tone-audiometrypreoperative-evaluation-overview

American audiologist who described the artefactual depression of bone-conduction thresholds (maximal at 2 kHz) accompanying stapes fixation, the eponymous Carhart notch. Recognising that this bone-conduction dip is mechanical and reverses after surgery transformed how surgeons interpret the audiogram before and after ossicular surgery.

See also: carhart-notchaudiologic-discontinuity-vs-fixation

Re-operation on a previously reconstructed ear because of a failed or extruded prosthesis, displacement, recurrent disease, or persisting air–bone gap. Revision ears are more hostile — scarred, sometimes infected, with altered landmarks — so outcomes are generally poorer than primary surgery, and cartilage reinforcement and stabilisation techniques are used liberally.

See also: revision-ossiculoplastyprosthesis-displacement

American otologist who classified the inflammatory and drainage status of the ear into prognostic groups, drawing attention to how a wet, poorly aerated, or recurrently infected ear undermines reconstruction. The Bellucci classification remains a reference for staging the biological environment of ossiculoplasty.

See also: bellucci-spite-classificationear-environment-risk-scores

The second cochlear window, closed by the secondary tympanic membrane and located in the round window niche. It allows perilymph to move in response to stapes motion at the oval window, providing the pressure-release that lets the cochlear partition vibrate. Preserved phase difference between the two windows is the basis of round-window shielding and the acoustic rationale for reconstruction.

See also: round-window-cochlea-interfacesound-transmission-physics

The acoustic requirement that sound preferentially drive the oval window while the round window is acoustically shielded, preserving the phase difference needed to move the cochlear partition. If both windows are stimulated equally (round window unshielded), the pressure differential collapses and hearing is poor, which is why reconstructions and grafts must not obliterate or expose the round window inappropriately.

See also: round-window-cochlea-interfaceeffect-of-ossicular-defects

The thin plate of bone forming the lateral wall of the epitympanum and the superior margin of the tympanic membrane. Its erosion is a classic radiological and intraoperative sign of attic cholesteatoma, and the defect often must be reconstructed (for example with cartilage) at the time of ossiculoplasty to prevent retraction and recurrence.

See also: tympanic-cavity-boundariesimaging-ossicular-erosion

A deep recess of the retrotympanum medial to the facial nerve and pyramidal eminence, bounded by the ponticulus and subiculum. Its variable depth makes it a notorious hidden reservoir for residual cholesteatoma that is difficult to inspect with the microscope and a key reason endoscopic visualisation is valued before reconstruction.

See also: tympanic-cavity-boundariesotoendoscopy-otomicroscopy

A mnemonic system that grades the ossiculoplasty environment by Surgery (prior operations), Prosthesis (type and stability), Infection, Tissue (mucosal and graft status), and Eustachian-tube function. Each adverse factor worsens the prognosis, and SPITE is used alongside MERI and OOPS to set realistic expectations and decide between primary and staged reconstruction.

See also: bellucci-spite-classificationear-environment-risk-scores

A deliberate two-operation strategy in which disease clearance and middle-ear rehabilitation are done first, and ossicular reconstruction is deferred (typically 6–12 months) to a second-look procedure once the ear is dry, aerated, and free of residual disease. Staging improves both the safety of cholesteatoma surgery and the acoustic environment into which the prosthesis is placed.

See also: staged-surgery-strategyprimary-vs-staged-decision

Creation of a small calibrated fenestra in a fixed stapes footplate (as in otosclerosis or tympanosclerotic fixation) into which a piston prosthesis is placed from the incus or malleus. It is preferred over the larger stapedectomy because the small opening preserves perilymph dynamics and reduces inner-ear trauma; it may be combined with ossicular reconstruction when fixation and discontinuity coexist.

See also: combined-stapedotomy-ocrfootplate-reconstruction

The smallest and most medial ossicle, consisting of a head, anterior and posterior crura, and a footplate seated in the oval window. It transmits sound energy from the incus into the cochlear fluids and is held by the annular ligament. An intact, mobile stapes (or at least a mobile footplate) is the single most important determinant of a good ossiculoplasty result.

See also: stapes-footplate-anatomyossicular-chain-anatomy

The thin, tough fascia overlying the temporalis muscle, the classic autograft for tympanic-membrane reconstruction. Harvested easily through the same incision, it is well vascularised, becomes incorporated reliably, and provides a low-mass drum graft, though in high-risk or retraction-prone ears cartilage is often preferred for its greater rigidity.

See also: temporalis-fascia-graftgraft-materials-overview

A lightweight, stiff, highly biocompatible metal that has become the dominant prosthesis material, allowing low-mass open designs that transmit sound efficiently and are easy to visualise and trim. Titanium devices show good hearing results and reasonable extrusion rates, though a cartilage cap is usually interposed at the drum to protect against the slightly higher extrusion seen with bare metal.

See also: titanium-prosthesesideal-prosthesis-criteria

A prosthesis that conducts sound from the tympanic membrane or malleus directly to the stapes footplate when the stapes superstructure is absent. Because it rests on the mobile footplate over a longer, less stable column, a TORP is more prone to displacement and gives, on average, a poorer air–bone gap than a PORP, so footplate stabilisation and a cartilage cap are commonly added.

See also: torp-design-biomechanicsstapes-absent-torp-technique

The air-filled space of the middle ear bounded by the tympanic membrane laterally, the labyrinthine wall medially, and the tegmen, jugular wall, carotid wall, mastoid, and Eustachian-tube opening forming its other surfaces. It is conventionally divided into the epitympanum, mesotympanum, hypotympanum, protympanum, and retrotympanum, and houses the ossicular chain that ossiculoplasty reconstructs.

See also: tympanic-cavity-boundariesmiddle-ear-anatomy-overview

A flap of canal skin and the attached tympanic membrane elevated to enter the middle ear transcanally, the standard exposure for most ossiculoplasties. Incisions are placed in the posterosuperior canal and the flap reflected anteriorly on the malleus, taking care to preserve the chorda tympani and the annulus so the drum can be returned and heal.

See also: tympanomeatal-flaptranscanal-approach

An objective measure of middle-ear admittance as ear-canal pressure is swept, plotted as a tympanogram. Type A is normal; type B (flat) suggests effusion or perforation; type C indicates negative pressure; a deep, high-compliance type Ad pattern suggests ossicular discontinuity, while a shallow As pattern suggests fixation. It complements the audiogram in distinguishing the mechanism of a conductive loss.

See also: tympanometry-impedanceaudiologic-discontinuity-vs-fixation

The Wüllstein category in which sound is conducted directly from the tympanic membrane (or a graft) onto the head of an intact, mobile stapes, with the malleus and incus absent or removed. The classic 'columella' arrangement can be created by laying the drum onto the stapes head (myringostapediopexy) or by interposing a PORP, and it forms the conceptual basis of modern partial-prosthesis reconstruction.

See also: wullstein-tympanoplasty-typesstapes-present-porp-technique

Horst Wüllstein's five-part classification of tympanoplasty introduced in the 1950s, describing reconstruction by the level at which the sound-conducting system is rebuilt. Types I–III preserve progressively fewer ossicles (myringoplasty, ossiculoplasty onto the incus, and direct drum-to-stapes type III), while types IV and V address an absent stapes superstructure and a fixed footplate respectively. It remains the conceptual backbone for describing what each reconstruction is doing.

See also: wullstein-tympanoplasty-typesreconstruction-techniques-overview