title: Value of routine plain x-ray position checks after cochlear implantation.
abstract: OBJECTIVE
  To analyze the value of a routine x-ray position check after cochlear implantation and to assess if an increased resistance during electrode insertion is a sufficient predictor of electrode misplacement.
  
  
  METHODS
  Retrospective data collection.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Plain x-rays (Stenvers' projection) and the respective surgery reports of 218 patients having received cochlear implantation (243 ears) were analyzed for possible electrode misplacements and intraoperative conspicuities during electrode insertion.
  
  
  RESULTS
  Electrode misplacement (tip-over, loop, kinking, scalar transition, and incomplete insertion) was observed in 8% of the entire study cohort, but only in 5% if cases with inner ear dysplasia or labyrinthine ossification (n = 28) were excluded from analysis. Intraoperatively, an increased resistance during electrode insertion was found in 16% but only in 8% when cases with inner ear dysplasia or labyrinthine ossification were excluded. The intraoperative finding of an increased resistance during electrode insertion had a sensitivity of 55% and a specificity of 88% for predicting radiographically confirmed electrode misplacements (positive predictive value, 29%; negative predicting value, 96%).
  
  
  CONCLUSIONS
  Nearly half of the cases of electrode misplacement would have been overlooked if radiographic position checks would have been done only in patients with intraoperative conspicuities during electrode insertion. This finding advocates routine radiographic position checks, although electrode misplacements are relatively rare in patients with regular inner ear anatomy.
authors.affiliation: *Institute for Clinical Radiology, and †Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig Maximilian University, Munich, Germany.
authors.forename: Franziska
authors.initials: F
authors.lastname: Dirr
authors.forename: John Martin
authors.initials: JM
authors.lastname: Hempel
authors.forename: Eike
authors.initials: E
authors.lastname: Krause
authors.forename: Joachim
authors.initials: J
authors.lastname: Müller
authors.forename: Alexander
authors.initials: A
authors.lastname: Berghaus
authors.forename: Birgit
authors.initials: B
authors.lastname: Ertl-Wagner
authors.forename: Thomas
authors.initials: T
authors.lastname: Braun
mesh_terms: D000328:Adult; D003051:Cochlea / Q000000981:diagnostic imaging* / Q000601:surgery; D019929:Cochlear Implantation; D003054:Cochlear Implants; D007758:Ear, Inner / Q000000981:diagnostic imaging* / Q000601:surgery; D005260:Female; D006801:Humans; D008297:Male; D011184:Postoperative Period; D011859:Radiography; D012680:Sensitivity and Specificity