9Combined Stapedotomy and Ossiculoplasty

FTwo faults in one chain

Most ossiculoplasty deals with a single fault: a chain that has come apart. A strut is slotted in to carry sound across the gap, and as long as the stapes can move, hearing returns. This module is about the harder ear, where the chain has two faults at once — it is both interrupted somewhere along its length and, at its inner end, anchored to a footplate that will not move. The eroded long process of the incus leaves a discontinuity; a tympanosclerotic plaque or an otosclerotic focus glues the footplate into the oval window. Either fault alone causes a conductive loss; together they produce a large, stubborn gap that no single manoeuvre can close [2019].

The clinical picture is most familiar in tympanosclerosis, where the same disease process that thinned and divided the ossicles also calcified the oval-window margin, but the combination is also seen in revision chronic-ear surgery, in advanced otosclerosis that has spread to involve a remodelled chain, and in some congenital malformations [2002, 2003]. Whatever the cause, the surgical problem is the same and it has a single guiding idea: the fixed footplate must be made mobile before the rebuilt chain can do any good. The rest of the module unpacks why, how, and how well it works.

FWhy the footplate must move first

The stapes footplate is the last mobile interface between the air-filled middle ear and the fluid-filled cochlea. Sound only enters the inner ear because the footplate rocks in the oval window and pushes perilymph, which the compliant round window lets escape. If that footplate is fixed, the cochlear fluids cannot be displaced, and it makes no difference how elegantly the lateral chain is rebuilt — a perfectly positioned prosthesis transmitting onto a stationary platform moves nothing. This is the crucial idea for a student to carry away: ossiculoplasty cannot succeed over a fixed footplate. The reconstruction has to terminate on an oval window that can move.

That is why a chain with both faults cannot be treated as an ordinary discontinuity. The discontinuity tempts the surgeon to reach for a familiar PORP or TORP, but a strut dropped onto a fixed footplate simply hands the sound energy to an immovable wall. The footplate problem must be solved — classically by a small-fenestra stapedotomy that opens a controlled window in the footplate and so frees the oval window to move again. Only when the window is mobile does rebuilding the lateral chain make acoustic sense. The combined operation is, in essence, two procedures stitched into one: a stapedotomy to restore mobility, and an ossiculoplasty to restore continuity, in that order.

TSequencing the operation

Sequence is everything. The surgeon first confirms an ear in which it is safe to open the labyrinth at all: an intact drum, healthy mucosa, good aeration and measurable cochlear reserve. The chain is then mapped — identifying both the discontinuity and the fixation by palpation — so the full extent of the problem is known before anything irreversible is done. The footplate is dealt with next: a precise, small-fenestra stapedotomy frees the oval window, which is more durable and predictable than blunt mobilisation of a tympanosclerotic footplate [2002]. Throughout, the open window is protected from blood and suction, because an exposed vestibule is unforgiving.

Only then is the lateral chain reconstructed, so that the new strut transmits to a footplate that already moves. Doing it the other way round — rebuilding the chain and trying to mobilise the footplate through the finished construct — is mechanically awkward and risks displacing the very reconstruction just completed. The step-through below walks the sequence: dry, safe ear → map the defect → free the footplate → reconstruct onto the mobile window → tension, centre and seal. Watch the oval window change from fixed to mobile before the strut ever appears.

Two cautions follow from the sequence. First, an open oval window in a wet, infected, or poorly aerated field is a recipe for labyrinthitis and a dead ear; if the field cannot be made dry and quiet, the footplate work should be deferred. Second, the stapedotomy itself must be gentle and controlled: the large prospective stapedotomy experience shows that a careful small fenestra closes the gap reliably with a very low rate of severe sensorineural loss, and that safety margin must be preserved when the same manoeuvre is bolted onto a reconstruction[2006].

TCoupling the reconstruction to the oval window

Once the footplate moves, how the chain is rebuilt depends on what remains. When a healthy, mobile stapes superstructure is present above the freed footplate, the surgeon can couple to the stapes head in the usual way with a partial prosthesis (PORP) or an autograft, and the construct is stable and forgiving. The harder situation is when the superstructure is absent or unusable and the reconstruction must rest on the footplate itself. A free strut balanced on a bare, freshly opened footplate is prone to wobble and displacement, and its coupling is unreliable.

This is where a dedicated stapes footplate prosthesis earns its place. A purpose-made device that seats stably in the oval window gives a reproducible platform for the rest of the construct, and the difference in outcome is not subtle: in a comparative series, total reconstructions using a titanium footplate prosthesis closed the air-bone gap to within 20 dB far more often, and displaced less, than those resting on the bare footplate[2015]. The chart below sets that contrast against the benchmark of an isolated stapedotomy. Whichever device is used, the universal rules of ossiculoplasty still apply: correct length and gentle tension so the construct neither floats nor over-penetrates the vestibule, a centred head beneath the drum or malleus where vibration is greatest, and a small soft-tissue graft to seal the fenestra without loading or immobilising it.

A note on over-penetration: a strut that is too long and presses deep into the vestibule can provoke vertigo and sensorineural injury, while one that is too short loses coupling. The reconstruction over a stapedotomy is therefore a balance — enough length to drive the fenestra, not enough to invade the inner ear — and the margin for error is smaller than in a routine ossiculoplasty because the window is open.

CWhat the evidence shows

The reassuring headline is that the combined ear is reconstructable. Stapedotomy for tympanosclerotic stapes fixation — the commonest setting for this combination — has been shown to be both safe and efficient even though most such ears also need lateral-chain repair, with meaningful gap closure and no dead ears in a focused series [2002]. More broadly, analyses of ossicular pathology in chronic ear disease find that the typeof lesion — whether the chain is discontinuous, fixed, or both — does not by itself determine whether reconstruction succeeds, provided the ear is otherwise favourable[2019]. In other words, the additional fixation does not doom the result; it simply adds a step.

What does drive the result is the same set of prognostic factors that govern any ossiculoplasty: the state of the remnants, the health of the middle-ear mucosa, the presence of drainage, and prior surgery[2001]. A fixed footplate worsens the prognostic category chiefly because it usually signals more advanced disease and a more complex reconstruction, not because the footplate work itself is hazardous in experienced hands. And when the reconstruction must couple to the footplate, the evidence is concrete that a stable platform matters: the footplate-prosthesis advantage in gap closure and displacement is the single most actionable finding in the comparative literature [2015]. Set against the >94% gap closure of isolated stapedotomy, the combined operation is more demanding and its results more modest — but in the right ear it converts a large, fixed, discontinuous loss into serviceable hearing[2006].

COne stage or two, and a dry, safe ear

The last decision is whether to do everything in one sitting or to stage it. The governing principle is the safety of opening the labyrinth. In a dry, well-aerated, disease-free ear with good cochlear reserve and clear oval-window access, a single-stage combined stapedotomy and ossiculoplasty is reasonable and efficient. When the ear is wet, poorly aerated, harbours active disease, or offers hazardous access to the footplate, the prudent course is to stage: make the ear safe and dry first — clearing disease, securing aeration, healing the drum — and return for the stapedotomy and reconstruction once an open window will not be bathed in blood, mucus, or infection [2001, 2003]. The decision aid below combines those factors into a single verdict.

Borderline cochlear reserve deserves its own caution: with little usable hearing to recover, the calculus shifts, because opening the oval window always carries a small but real risk of a dead ear, and that risk is hard to justify when the potential gain is slim. In such ears a frank discussion about amplificationas an alternative to surgery is part of good practice. The unifying message of the module is therefore simple. A chain that is both discontinuous and fixed is two problems, solved in order: free the footplate first, then rebuild the chain onto a window that moves, and do it in a dry, safe ear — or wait until you have one. Get the sequence and the field right, and a daunting combined defect becomes a reconstructable one.