title: Resonance frequency analysis of osseo-integrated implants for bone conduction in a pediatric population - a novel approach for assessing stability for early loading.
abstract: OBJECTIVE
  The purpose of our study was to directly measure the stability of a bone anchored hearing device (BAHD) abutment using resonance frequency analysis (RFA) in a pediatric population. RFA was used to guide early loading of the abutment following single stage surgery.
  
  
  METHODS
  The principle behind RFA is to obtain a numerical value relating to stability. A Smartpeg (1 cm commercially manufactured attachment) is screwed onto the abutment - its resonance in a magnetic field is measured with an Osstell recording device. The degree of movement (vibration) is inversely proportional to the stability of the abutment and a numerical figure, the Implant Stability Quotient (ISQ), is derived. RFA measurements were obtained at surgery, 4 weeks and 16 weeks post implant surgery. Patients were fitted with the new CochlearTM Baha(®) BI300 series implant using a one-stage procedure and based on RFA stability measures, loading of the sound processor occurred any time from 1 week after implant surgery if the RFA measure was 60 units or over.
  
  
  RESULTS
  Twenty two consecutive patients were recruited. Eight patients had bilateral BAHD's fitted giving a total of 30 implants. The age range was 2-16 years with an average age of 9 years at time of fitting. The time interval from surgery to loading the processor ranged from 1 to 16 weeks, with an average time of 6 weeks. The mean ISQ value at time of surgery was 61.29 (95% CI = 2.03), at 4 weeks was 61.92 (95% CI = 2.97) and at 16 weeks was 63.45 (95% CI = 3.18).
  
  
  CONCLUSIONS
  Our study shows we have been able to operate a successful program of earlier BAHD loading using single stage surgery in children. This is supported by favorable RFA measures of implant stability with average ISQ values of over 60 units.
authors: Newcastle BAHA Programme, ENT Department, Freeman Hospital, Freeman Road, High Heaton, Newcastle upon Tyne NE7 7DN, United Kingdom. Electronic address: clairemrennison@hotmail.com.
authors: Claire
authors: C
authors: McLarnon
authors: Newcastle BAHA Programme, ENT Department, Freeman Hospital, Freeman Road, High Heaton, Newcastle upon Tyne NE7 7DN, United Kingdom.
authors: Ian
authors: I
authors: Johnson
authors: Newcastle BAHA Programme, ENT Department, Freeman Hospital, Freeman Road, High Heaton, Newcastle upon Tyne NE7 7DN, United Kingdom.
authors: Tom
authors: T
authors: Davison
authors: Newcastle BAHA Programme, ENT Department, Freeman Hospital, Freeman Road, High Heaton, Newcastle upon Tyne NE7 7DN, United Kingdom.
authors: John
authors: J
authors: Hill
authors: Newcastle BAHA Programme, ENT Department, Freeman Hospital, Freeman Road, High Heaton, Newcastle upon Tyne NE7 7DN, United Kingdom.
authors: Beverly
authors: B
authors: Henderson
authors: Newcastle BAHA Programme, ENT Department, Freeman Hospital, Freeman Road, High Heaton, Newcastle upon Tyne NE7 7DN, United Kingdom.
authors: Denise
authors: D
authors: Leese
authors: Newcastle BAHA Programme, ENT Department, Freeman Hospital, Freeman Road, High Heaton, Newcastle upon Tyne NE7 7DN, United Kingdom.
authors: Suzanne
authors: S
authors: Marley
mesh_terms: D000158:Acoustic Impedance Tests / Q000379:methods; D000293:Adolescent; D000367:Age Factors; D001844:Bone Conduction / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006310:Hearing Aids; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000628:therapy*; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods; D016348:Osseointegration / Q000502:physiology*; D011446:Prospective Studies; D011475:Prosthesis Failure; D019919:Prosthesis Implantation / Q000379:methods*; D012307:Risk Factors; D012720:Severity of Illness Index; D053441:Suture Anchors; D016896:Treatment Outcome; D006113:United Kingdom
keywords: Bone anchored hearing aid; Hearing loss; Pediatric