title: Eliminating the limitations of manual crimping in stapes surgery: mid-term results of 90 patients in the Nitinol stapes piston multicenter trial.
abstract: OBJECTIVE
  To present our mid-term results of our multicenter study using the Nitinol self-crimping stapes piston, focusing on the interindividual variations of postoperative air-bone gap closures (ABGC), postoperative hearing results, and postoperative recurrences of conductive hearing loss and to compare these findings with our pilot group of patients.
  
  
  METHODS
  Prospective, multicenter cohort study involving three academic tertiary care referral centers from Australia, Switzerland, and the United States.
  
  
  METHODS
  Ninety patients with otosclerosis undergoing laser-stapedotomy with the Nitinol stapes piston were matched to reference patients from our titanium piston database. The effects of the self-crimping Nitinol piston on the postoperative ABGC, the postoperative interindividual air-bone gap (ABG) variations, and the postoperative hearing results were investigated 3, 6, 12, 18, and 24 months postoperatively. These data were statistically compared with the results of the control patients in our titanium stapes piston database and the results of our previously published pilot study.
  
  
  RESULTS
  The mean postoperative ABG and the interindividual variations of the postoperative ABG continue to be significantly smaller in the Nitinol group; the extent of ABGC now is significantly larger in the Nitinol piston group. The postoperative mid-term stability of ABGC was similar in both groups. No adverse reactions occurred during follow-up.
  
  
  CONCLUSIONS
  Our mid-term results continue to show that the self-crimping shape memory alloy Nitinol stapes piston overcomes the limitations of manual malcrimping in stapedotomy, thus simplifying and optimizing the surgical procedure. This so far has allowed reliable, safe, and consistent ABGC in patients with otosclerosis.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, Lions Ear and Hearing Institute, University of Western Australia, Fremantle, Australia. Gunesh.Rajan@health.wa.gov.au
authors.forename: Gunesh P
authors.initials: GP
authors.lastname: Rajan
authors.forename: Jason
authors.initials: J
authors.lastname: Diaz
authors.forename: Ruth
authors.initials: R
authors.lastname: Blackham
authors.forename: Robert H
authors.initials: RH
authors.lastname: Eikelboom
authors.forename: Marcus D
authors.initials: MD
authors.lastname: Atlas
authors.forename: Clough
authors.initials: C
authors.lastname: Shelton
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Huber
mesh_terms: D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D015331:Cohort Studies; D004867:Equipment Design; D005260:Female; D006314:Hearing Loss, Conductive / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011446:Prospective Studies; D012720:Severity of Illness Index; D013201:Stapes Surgery / Q000295:instrumentation* / Q000379:methods