Bone Anchored Hearing Surgery using a BHX implant manufactured by Oticon Medical

This is a observational study of pediatric patients undergoing bone anchored hearing surgery. The collected will be used to assess the implant stability development of the Ponto BHX implant during up to 24 months after implantation in a pediatric population undergoing BAHS. The study will also monitor the Ponto BHX implant safety and survival throughout the study period.

Implant stability will be assessed using resonance frequency analysis (RFA). This is a non-invasive technique using a SmartPeg (no 55) introduced into the abutment top. A probe is directed to the SmartPeg measuring the vibrations as a test for the stability of the interface between the fixture and the bone (osseointegration). The measurement renders Implant Stability Quotient (ISQ) 'numerical values from 1 to 100'; the higher the ISQ value, the higher the stability. Two perpendicular measurements will be performed at each site. The highest and lowest ISQ value obtained at each time point aree recorded. The Osstell ISQ instrument and SmartPegs from Osstell (Gothenburg, Sweden) will be used. Difference in mean of ISQ low at 6 months compared to surgery.