title: Morphology of the malleus handle and the comparison of different prostheses for malleostapedotomy.
abstract: OBJECTIVE
  To assess malleus morphology to characterize optimal sites for prosthesis attachment in malleostapedotomy and to examine attachment, position, and depth of penetration in the vestibule of the 3 most used prostheses.
  
  
  METHODS
  Ten mallei were processed for histologic examination with the light microscope. Using digitized video images of the histologic slices, the diameters, circumference, and shape of the specimen were determined. Implantation of 3 prostheses (Gyrus Nitinol piston, Storz titanium stapes piston, and Kurz malleovestibulopexy piston), was performed in 3 temporal bones for a total of 27 implantations.
  
  
  RESULTS
  The cross-section of the malleus just distal to the lateral process shows an inclined oval shape with a mean minimum diameter of 0.84 +/- 0.10 mm, a mean maximum diameter of 1.02 +/- 0.23 mm, and a mean circumference of 3.23 +/- 0.49 mm. The quality of attachment to the malleus, the position of the prosthesis piston, and the depth of penetration were reliable for the Storz titanium stapes piston, satisfactory though variable for the Gyrus Nitinol piston and poor for the Kurz malleovestibulopexy piston as judged by contact with the malleus surface and predictability of insertion depth into the vestibule.
  
  
  CONCLUSIONS
  The oval and inferoanteriorly inclined shape of the malleus distal to the lateral process requires the use of a prosthesis capable of molding itself to its surface for reliable attachment. To achieve the correct perpendicular position of the piston as it relates to the stapedotomy opening, individualized adaptation of the prosthesis shaft and loop to the anterior position of the malleus should be made in situ.
authors.affiliation: ENT Department, University of Regensburg, Regensburg, Germany. pingling.kwok@klinik.uni-regensburg.de
authors.forename: Pingling
authors.initials: P
authors.lastname: Kwok
authors.forename: Ugo
authors.initials: U
authors.lastname: Fisch
authors.forename: Markus
authors.initials: M
authors.lastname: Nussbaumer
authors.forename: Sven
authors.initials: S
authors.lastname: Herkenhoff
authors.forename: Jürgen
authors.initials: J
authors.lastname: Strutz
mesh_terms: D000497:Alloys; D001672:Biocompatible Materials; D003054:Cochlear Implants; D004429:Ear Ossicles / Q000033:anatomy & histology / Q000601:surgery; D006801:Humans; D008307:Malleus / Q000033:anatomy & histology* / Q000601:surgery*; D011138:Polytetrafluoroethylene; D011474:Prosthesis Design; D019919:Prosthesis Implantation; D013201:Stapes Surgery; D014722:Vestibule, Labyrinth / Q000502:physiology; D014732:Vibration
chemical_list: D000497:Alloys; D001672:Biocompatible Materials; C013616:nitinol; D011138:Polytetrafluoroethylene