title: Three-dimensional analysis of the vestibular end organs in relation to the stapes footplate and piston placement.
abstract: OBJECTIVE
  Measurements of the proximity of the membranous labyrinth to the stapes footplate show considerable variation. Largely, such measurements have been from histologic sections of fixed temporal bones, which may be affected by shrinkage artifact and perspective distortion in the 2-dimensional plane. To overcome these problems, the present study undertook an analysis of the 3-dimensional (3D) architecture of the relationship of the stapes to the membranous labyrinth using high-resolution X-ray micro-computed tomography.
  
  
  METHODS
  Eleven temporal bones were fixed with Karnovsky's fixative (known to minimize shrinkage), soaked in 2% osmium tetroxide, and scanned in a micro-computed tomography scanner. The otic capsule was intact to exclude sectioning artifact, and no alcohol was used to avoid tissue shrinkage. Measurements were taken in a vertical plane to provide distances from the utricle and saccule to the footplate, and 3D reconstruction of the spatial relationship of these structures was carried out. The relationship of these structures to a stapes piston also was studied.
  
  
  RESULTS
  The safest area of piston placement was the central and inferior part of the footplate. This was safe up to 0.5 mm depth at all areas except posterosuperiorly where the utricular macula is, on average, only 0.61 mm away from the footplate. The angle of insertion of the piston also influences the end result.
  
  
  CONCLUSIONS
  Two-dimensional information about vestibular end organ location should serve as a guideline only because the operative field is 3D, and the relationship of the piston to the vestibular labyrinth changes with the angle of placement.
authors.affiliation: Department of Otology, Neurotology and Skull Base Surgery, Royal Prince Alfred Hospital, Sydney, Australia. payalmukherjee@hotmail.com
authors.forename: Payal
authors.initials: P
authors.lastname: Mukherjee
authors.forename: Hilal
authors.initials: H
authors.lastname: Uzun-Coruhlu
authors.forename: Ian S
authors.initials: IS
authors.lastname: Curthoys
authors.forename: Allan S
authors.initials: AS
authors.lastname: Jones
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Bradshaw
authors.forename: David V
authors.initials: DV
authors.lastname: Pohl
mesh_terms: D006801:Humans; D021621:Imaging, Three-Dimensional; D013199:Stapes / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D013701:Temporal Bone / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014722:Vestibule, Labyrinth / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D055114:X-Ray Microtomography