RESUMO
The Kraus K-Helix Crown and Piston prostheses are novel, newly designed, MRI compatible, titanium ossicular replacement prostheses that have received U.S. Food and Drug Administration clearance in March of 2008 for ossiculoplasty. Reconstruction is indicated to restore sound conduction of the ossicular chain during tympanoplasty in chronic and non-chronic ears. The prostheses have been specifically developed for reconstruction of an eroded or absent long process of the incus and an eroded or absent stapes superstructure. They may be used with or without glass-ionomer cement. The prostheses may be implanted incus-to-stapes or malleus-to-stapes (K-Helix Crown) or may be implanted incus-to-footplatelneo-membrane or malleus-to-footplate/neo-membrane (K-Helix Piston). The K-Helix Piston is useful during revision stapedectomy when an eroded long process of the incus is encountered. By coating the K-Helix prostheses with glass-ionomer cement, it is possible to perform "endoskeletal ossicular reconstruction" which greatly enhances long-term prosthesis stability and avoids contact with the tympanic membrane. The prostheses may be custom-fit to reconstruct each individual patient's anatomy. Preliminary hearing results in a small cohort of patients at one year indicate very satisfactory hearing results with closure of the air-bone gap in the majority of patients. The ENT OR nurse plays a role in the use of specialized, adjunctive OR equipment that is used with the technology, is required for the preparation of glass-ionomer cement, and provides patients with important educational information concerning reconstructive otologic procedures.