title: Comparison of two different titanium couplers for an active middle ear implant.
abstract: OBJECTIVE
  To compare surgical methods, functional gain, and speech discrimination using two different coupling methods for an active middle ear implant. Of several couplers enabling placement of the active element at various locations, two function directly at a cochlear membrane, bypassing a missing or malformed ossicular chain. This study evaluates whether either of these methods is more beneficial.
  
  
  METHODS
  Retrospective case review.
  
  
  METHODS
  ENT surgical clinic.
  
  
  METHODS
  Forty-seven German-speaking patients with moderate to severe mixed hearing loss.
  
  
  METHODS
  Records of patients implanted with either a round window (RW) or oval window (OW) coupler and active implant were examined. Preoperative and postoperative bone and air-conduction thresholds, auditory gain, and speech perception were compared.
  
  
  METHODS
  Functional gain, Freiburger monosyllables in quiet.
  
  
  RESULTS
  The range of hearing benefit shown by functional gain in patients implanted with the RW coupler (median) was between 22.5 dB (at 0.25 kHz) and 52.5 dB (2 and 3 kHz). In the OW group, improvement was similar, ranging from 21 dB (at 8 kHz) to 50 dB (1 and 2 kHz). Patients in both groups showed a similar improvement in speech recognition. Median preoperative unaided word recognition was 0% at 60 dB HL for both patient groups, improved postoperatively in both groups to median 85% correct at 65 dB HL and 95% at 80 dB HL.
  
  
  CONCLUSIONS
  Placement of an active middle ear implant using the RW and the OW coupler was found to be safe, although the surgical methods differ. Safety and efficacy of both couplers present no significant differences.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Hannover Medical School, Hannover, Germany.
authors.forename: Burkard
authors.initials: B
authors.lastname: Schwab
authors.forename: Rolf
authors.initials: R
authors.lastname: Salcher
authors.forename: Magnus
authors.initials: M
authors.lastname: Teschner
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004432:Ear, Middle / Q000601:surgery*; D005260:Female; D006310:Hearing Aids; D034381:Hearing Loss / Q000601:surgery*; D006320:Hearing Tests; D006801:Humans; D008297:Male; D008875:Middle Aged; D009998:Ossicular Prosthesis; D013506:Otologic Surgical Procedures / Q000295:instrumentation* / Q000379:methods; D012189:Retrospective Studies; D013067:Speech Perception; D014025:Titanium; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D014025:Titanium