1Grafts and Reconstruction Materials: Chapter Overview

FTwo families of materials

Every ossiculoplasty ends the same way: a chosen material is laid into the middle ear to rebuild what disease has taken. This chapter is about that material. The modern era began when Wullstein systematised reconstructive tympanoplasty and showed that the surgeon’s task was not merely to eradicate disease but to rebuild a sound-conducting apparatus from grafts and prostheses [1956]. Since then the toolkit has grown, but it still falls into two broad families that you should be able to name and contrast on demand.

• Biological materials — the patient’s own tissue (autografts: cartilage, the eroded incus or malleus head, cortical bone) and, historically, donor tissue (homografts: cadaveric ossicles, cartilage, fascia).
• Alloplastic materials— manufactured synthetics: ceramics such as hydroxyapatite, metals such as titanium, the older porous polymers, and injectable biocements.

No single material is ideal. The properties one wants — biocompatibility, resistance to resorption and extrusion, mechanical stability, ease of sculpting, and acoustic fidelity — pull against one another, and the right answer is the material whose trade-offs best fit the ear in front of you. The chapters that follow drill into individual materials; this overview maps the whole landscape so the detail has somewhere to land.

A useful way to hold the field in mind is to remember that biology is the default for the drum and the adjuncts, while engineering increasingly owns the strut. Cartilage and fascia rebuild the tympanic membrane; sculpted autograft, titanium, hydroxyapatite, or cement bridges the ossicular gap. Most real reconstructions are hybrids of the two families— a synthetic prosthesis capped with the patient’s own cartilage being the commonest example.

FAutografts: the patient’s own tissue

Autografts — tissue harvested from the same patient during surgery — were the original ossicular substitutes and remain a mainstay. Their appeal is biological: there is no immune rejection and no disease-transmission risk, they are inexpensive and immediately available, and they provoke minimal foreign-body reaction, which translates into very low extrusion rates, typically only a few percent. The classic technique is incus interposition, popularised by Austin and Shea in the 1960s, in which a partly eroded incus is removed, sculpted, and re-seated to bridge the malleus and stapes. Where ossicles are unsalvageable, cortical bone from the mastoid can be carved into a strut, though it is prone to slow resorption.

How do autografts perform? In a randomised comparison for Austin type A defects (eroded incus, intact stapes superstructure), an autologous incus closed the air–bone gap to within 20 dB in 65% of ears, against 35% for a titanium prosthesis, with fewer complications in the autograft arm [2017]. That result captures the autograft’s strengths in a favourable ear: when the host bed is healthy and the ossicle is salvageable, the patient’s own bone is hard to beat.

The limitations are equally real. Sculpting an ossicle under the microscope is time-consuming and operator-dependent; the graft may not be available or structurally adequate in heavily diseased ears; and autograft bone can ankylose to the facial canal, annulus, or promontory, producing delayed-onset conductive loss that complicates revision. The gravest concern is specific to cholesteatoma: reusing an ossicle enveloped by matrix risks seeding residual squamous disease. Histological study shows ossicles can be reused safely only after meticulous surface clearance — and that gross inspection alone does not reliably exclude microscopic disease [2003]. This single risk explains much of the modern shift away from autograft reuse in cholesteatoma surgery.

TCartilage: the workhorse adjunct

If one material defines contemporary reconstruction, it is cartilage— usually harvested from the tragus or concha. Cartilage is an autograft, but it deserves its own section because it does a different job from a sculpted ossicle: it rebuilds and reinforces the drum, and it protects the chain. Its decisive property is durability. Cartilage resists resorption and tolerates the hostile middle ear— the moist, poorly aerated, retracting environments where a fascia-only graft fails. In a 1,000-patient series, cartilage tympanoplasty gave reliable anatomical and audiological results precisely in the difficult ears (cholesteatoma, atelectasis, recurrent perforation) that defeat other materials [2003].

Cartilage plays three roles in ossiculoplasty:

• Drum reconstruction— as a full plate, palisades, or an island graft to rebuild a perforation or a retraction-prone, atelectatic membrane.
• Prosthesis protection— as a thin shield interposed between an alloplastic prosthesis head and the drum, preventing the synthetic from extruding through the membrane.
• Scaffolding— as a shoe, shim, or buttress that stabilises a prosthesis over the stapes or footplate and resists displacement.

The cost of cartilage is acoustic: it is stiffer and heavier than the native drum, and a large, thick plate dampens the high frequencies. The art lies in using just enough — a thin shield, a small island — to gain durability without paying an audible penalty. Note too that the protective role is most important in unfavourable ears: a titanium head can sit directly against a healthy, well-ventilated drum with acceptable extrusion, and in such ears most failures relate to membrane retraction rather than to the absence of a cartilage shield [2014]. Cartilage is insurance you buy when the ear looks risky.

THomografts: a historical detour

Homografts— ossicles, cartilage, or fascia from cadaveric donors, preserved by freeze-drying, irradiation, or chemical fixation — were once an attractive solution when autologous tissue was unavailable. Donor ossicles offer near-native anatomy and acoustic impedance, and they spare the surgeon the labour of sculpting. For a time they were a standard option in revision and total-loss reconstruction.

They have, however, been almost entirely abandoned in most centres, for three converging reasons:

• Disease transmission.The risk of transmitting viral or prion disease — HIV, hepatitis, and above all Creutzfeldt–Jakob disease — is the dominant concern. Sterilisation by irradiation or formalin reduces but does not unequivocally eliminate prion infectivity, and aggressive sterilisation degrades the graft’s collagen and mechanical integrity.
• Logistics and regulation. Homografts demand tissue banking, strict handling protocols, and regulatory compliance that are impractical for routine middle-ear surgery.
• Inferior durability. Compared with autografts, homografts show higher resorption and ankylosis rates, leading to delayed hearing deterioration and revision.

The lesson is conceptual rather than practical: homografts taught the field that biological congruence is not enough. A material must also be safe, durable, and logistically feasible — criteria that pushed the field toward sterile, standardised alloplasts. Homografts survive today only in niche settings where alloplasts are unavailable or specifically declined.

TAlloplasts, cements, and hybrids

Alloplastic materials are synthetic, sterile, and made to consistent geometry, with no donor risk. They have evolved through generations. The earliest porous polymers — Plastipore, Polycel, and PTFE (Teflon)— were cheap and easy to handle but disappointed in the long run with high extrusion and foreign-body reaction; they are now largely historical. Two material classes dominate the modern strut:

Hydroxyapatite, a calcium-phosphate ceramic, was the turning point: its composition mirrors bone mineral, so it is exceptionally biocompatible and can sit directly against the drum, with hybrid HA-head designs achieving extrusion rates around 4% [1992]. Its drawback is brittleness. Titaniumis the current benchmark: light, rigid, infinitely configurable into PORPs and TORPs, and with extrusion rates of only 1–2% — but a bare titanium head is usually capped with cartilage to keep it from eroding through the membrane [2004].

Biocements deserve special mention as an elegant solution to one specific problem. For isolated erosion of the long process of the incuswith otherwise intact, mobile ossicles, a drop of hydroxyapatite or glass-ionomer cement can rebridge the gap in situ without sculpting or a separate prosthesis. Reviews report air–bone gap closure to within 20 dB in roughly 80–94% of such cases, with low infection and extrusion [2014]. Finally, hybrid prostheses— an HA head on a titanium or polymer shaft, often capped with the patient’s cartilage — deliberately marry the families to get biocompatibility at the drum and handling strength in the shaft.

A reassuring pattern runs through the comparative literature: across most modern materials, the air–bone gap closes to within 20 dB in roughly 60–80% of ears, and differences between well-chosen materials are modest. The middle-ear environment and surgical technique usually matter more than the material itself. No prosthesis rescues a non-aerated, fibrotic, or actively diseased ear.

CChoosing a material at the microscope

Material selection is a decision made with the ear open, weighing the defect, the host bed, and the salvageable tissue. A few principles convert the catalogue above into operative judgement:

• Match the material to the defect.Isolated long-process erosion with intact mobile ossicles calls for the smallest solution — bone cement or a short prosthesis — not a whole strut from the footplate [2014].
• Let the host bed set the risk. In a healthy, well-aerated ear, a salvageable autograft or a bare-headed HA prosthesis performs well; in a diseased, atelectatic, or retracting ear, reach for cartilage to reinforce the drum and shield the prosthesis [2003, 2014].
• Respect the disease. In cholesteatoma, the residual-disease risk of reusing an enveloped ossicle usually tips the balance toward a sterile alloplast and a clean second look [2003].
• Default to a hybrid.A titanium or HA strut capped with the patient’s own cartilage is the modern workhorse, combining the strengths of both families [2004, 1992].
• Remember the autograft in the favourable ear.When the incus is salvageable, the stapes is intact, and the ear is dry and aerated, the patient’s own bone gives excellent, low-extrusion results at no cost [2017].

The unifying idea of this chapter is that materials are tools, not totems. Each family earns its place by a particular virtue — the autograft’s biological safety, cartilage’s durability, hydroxyapatite’s bone-like tolerance, titanium’s versatility, cement’s simplicity — and the skilled surgeon keeps the whole shelf in mind, choosing the one whose trade-offs best suit the ear and the defect. The detailed chapters that follow examine each in turn; the survey here is the map you carry into them.