| 摘要 |
An improvement in an otic prosthesis of the type used in ossicular reconstruction of the sound-conducting mechanism of the middle ear is provided. The improvement comprises a movable joint which connects a head portion and a shaft portion whereby there is provided a flexible, variably angled prosthesis, which can be readily set in position in the middle ear against the tympanum during surgical implantation. The movable joint permits the so-connected shaft portion to move in at least a single plane normal to the head portion and can itself be readily set against either retained bony elements of the sound-conducting mechanism or against tissue grafted into the aperture (oval window) between the middle and the inner ear. The movable joint is responsive to tympanic vibrations and the prosthesis exerts a minimized pressure on the tympanum during surgical implantation and thereafter it also resists dislodgment within or extrusion from the middle ear. The mounting means is characteristically a ball-and-socket joint whereby the ball is attached to the shaft and the socket to the head. The head portion of the prosthesis is preferably constructed entirely of a porous, biocompatible material which enables rapid tissue ingrowth. The shaft portion, in a preferred embodiment, is also formed of the same porous material thus enabling tissue ingrowth at the oval window-engaging end of the device.
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