Short- and long-term results with implantable transcutaneous and percutaneous bone-conduction devices

To compare the percutaneous bone-anchored hearing aid (BAHA; type NBC-HC-200, Nobel Biocare, Gothenburg, Sweden) and the transcutaneous temporal bone stimulator (TBS; Xomed-Treace, Jacksonville, Fla) with conventional hearing aids and to evaluate long-term results.

In a prospective clinical study, the new implantable bone-conduction devices were compared with the patients' previous conventional hearing aids. Speech perception in quiet and in noise were studied, and a questionnaire concerning the actual use of the device and speech recognition was administered. During follow-up that exceeded 4 1/2 years, relevant technical and medical problems were documented.

Forty-one successive subjects who were fitted with a BAHA and 17 subjects who were fitted with a TBS.

In most subjects who had previously used a bone-conduction device, the new BAHA and TBS devices led to improved or comparable results on speech recognition tests and the questionnaire. However, among the subjects who had previously used air-conduction hearing aids, the results were ambiguous. In the long-term, the percentage of nonusers in the BAHA group was 5% (2/39); in the TBS group, 65% (13/20). The main reasons for not using the TBS were insufficient gain and medical and technical problems. The vulnerability of the percutaneous coupling of the BAHA to trauma or inflammation was not a major issue; only 4 implants were lost during the total follow-up of more than 250 years.

Results indicate that the BAHA is the better choice.