Objective: Despite extensive soft tissue reduction, the most common complications associated with bone-anchored hearing aid systems, also known as bone-anchored hearing implants, are related to adverse skin reactions around the abutment. The necessary soft tissue reduction also adds complexity to the surgical procedure. This study aimed to evaluate the surgical and audiological outcomes of a new connective interface of the Cochlear (TM) Baha (R) BA400 device implanted using the one-stage surgical technique. Method: A multicentre, retrospective case series is presented, including data collected from three tertiary care institutions. Results: In total, 16 patients who had undergone bone-anchored hearing aid surgery over a 10- to 12-month period were assessed for hearing performance, implant stability and surgical complications. Conclusion: This case series indicates that new abutments with a hydroxyapatite coating can be implanted percutaneously without soft tissue reduction. Furthermore, device implantation using this surgical technique may have some advantages compared with a conventional device and procedure combination over 12- to 16-months of follow up.