Patent US4655776 - Prostheses for ossicular …
2. Smyth GD. Five-year report on partial ossicular replacement prostheses and total ossicular replacement prostheses. Otolaryngol Head Neck Surg 1982; 90(3 Pt 1):343–6.
Ossiculoplasty and Incus Replacement Prosthesis
Replacement prostheses can be divided into three types: Autograft, homograft (or allograft) and synthetic. Autografts are derived from the same patient and are usually obtained from the temporalis fascia, auricular cartilage (conchal or tragal) or the patient's own remaining ossicles. Homografts (or allografts) are obtained from other individuals of the same species but with a different genetic makeup. Disadvantages of homografts are the possibility of disease transmission1, biocompatibility, rejection and are more likely to become displaced. Homograft eardrums with complete ossicular chains have been used in the past to reconstruct severely damaged tympanic membranes and middle ears.1 Synthetic prosthesis are readily available, are presculptured and easy to use. However, they can have difficulties with displacement and extrusions. This was common with the porous polyethylene prostheses which were inserted in the early 1980s, that had a five year success rate as low as 22%.2 Newer prostheses using biocompatible materials, such as hydroxyapetite3 titanium4, have much higher success rates. Extrusion of synthetic prosthesis can be lowered by the placement of bone or cartilage between the eardrum and the prosthesis.
The Dornhoffer implant line is a premier offering of the latest technology in ossicular reconstruction prostheses. All of the heads in the Dornhoffer line feature a low profile contoured HA head. A groove is added to accommodate the malleus if present. The Dornhoffer product line consists of a 2mm fixed length partial, adjustable partial, adjustable total and a titanium footplate shoe. The footplate shoe greatly stabilizes the implant and can be adjusted to fit between the stapes crus remnants. A recent new feature incorporates windows in the HA head for increased visualization. The ALTO Dornhoffer is packaged with disposable sizers and preloaded in the patented ALTO adjuster which simplifies the need to properly size the implant.