The shape of a stapes prosthesis resembles a question mark. This is because of how it is used:
The curved part is placed around the long crus and fixed in different ways, depending on the model. The cylindrical shaft is passed through a hole in the footplate. This restores the mechanical sound conduction chain. Sound is now conducted from the eardrum via the residual ossicular chain and the transplant through the stapedial footplate.
Typically, stapes prostheses are used as a replacement for the stapedius, i.e. the stirrup bone, with the footplate fixed in place.
Common materials used to make the prostheses are platinum, a combination of platinum and PTFE and, increasingly, titanium.
In 2008, we began using a special combination of super-elastic nitinol with PTFE.
Information concerning the MRI-Safety is stored in PDF-format here >>