A new adhesive bonding material for the cementation of implantable devices in otologic surgery.
BACKGROUND
Presently, there are no U.S. Food and Drug Administration (FDA)-approved adhesive bone cements for the surgical fixation of prosthetic materials in the middle ear. A promising new cement, 4-META/MMA-TBB opaque resin, has shown remarkable adhesive properties as a bone cement in vivo. The cement is composed of 4-methacryloyloxyethyl trimellitate anhydride (4-META) and methyl methacrylate (MMA) as monomers and tri-n-butyl borane (TBB) as an initiator.


METHODS
An electromagnetic semiimplantable hearing device presently under development was implanted into the middle ear of six cats using 4-META/MMA-TBB resin to cement a titanium-encased magnet to the incus. The animals were subsequently killed (at a mean of 9.6 months) to assess the (temporal bones and specifically the magnet-incus complex in each animal.


RESULTS
The titanium-encapsulated magnet was firmly adherent to all incuses without any failure of the cement-bone interface. Histopathologic examination of the implanted temporal bones demonstrated lack of middle ear inflammation. Transmission electron microscopy of the incuses demonstrated a unique "hybrid layer" in the bone-side subsurface of the bone-cement interface that elucidates the mechanism of interfacial adhesion.


CONCLUSIONS
Our investigation highlights the special biomechanical properties as well as the biocompatibility of 4-META/ MMA-TBB resin that make it an attractive bone-bonding agent for use in otologic surgery, including its potential usefulness during ossicular reconstruction.
Maniglia
A J
AJ
Department of Otolaryngology-Head and Neck Surgery, Case Western Reserve University, University Hospitals of Cleveland, Ohïo 44106-5045, USA.
Nakabayashi
N
N
Paparella
M M
MM
Werning
J W
JW
D000818:Animals; D002415:Cats; D002484:Cementation; D004423:Ear / Q000601:surgery*; D004429:Ear Ossicles / Q000601:surgery; D013701:Temporal Bone / Q000648:ultrastructure; D014014:Tissue Adhesives
D014014:Tissue Adhesives