Single-stage Surgery Using the BHX Implant

Inclusion criteria test group: * Age 4-9 years * Indication for percutaneous bone-anchored hearing implant surgery with a BI300 implant * Insertion using the linear incision technique Inclusion criteria control group: * Children who underwent implantation of a wide diameter implant using two- stage surgery between 2012 and 2018 at the Radboudumc * Age 4-9 at the time of surgery * Linear incision technique was used during surgery Exclusion Criteria test group: * Inability to show up at all follow-up visits * Patients undergoing re-implantation * Diseases, syndromes or treatments known to compromise the bone quality at the implant site, e.g. radiotherapy, osteoporosis, diabetes mellitus. * Insufficient bone thickness ≤1mm, since conversion to two-stage surgery will be advocated Exclusion Criteria control group * Follow-up duration less than 1 year. * Diseases, syndromes or treatments known to compromise the bone quality at the implant site, e.g. radiotherapy, osteoporosis, diabetes mellitus (at moment of implantation)