Longitudinal Pediatric Outcomes of Second Generation Bonebridge (BCI602) and Osia 2 Implants

Introduction: To describe the longitudinal audiometric and surgical outcomes of the second-generation BonebridgeTM (BCI 602) or the Cochlear Osia®2 system in children and adolescents with conductive or mixed hearing loss or single-sided deafness.

Methods: A four-year retrospective review (October 2018-January 2023) of 52 children (59 implants) who underwent implantation with the Osia®2 (37 patients, 43 implants) or BCI 602 (14 patients, 16 implants) at a tertiary pediatric hospital. Inclusion criteria were < 19 years and completed preoperative unaided and postoperative aided audiometry. Pure-tone average air conduction (PTA AC) and bone conduction (PTA BC), aided thresholds, air-bone gap (ABG), functional gain (FG), effective gain (EG), speech reception threshold (SRT), and word recognition score (WRS) in quiet, were measured at 3 months and > 1 year postoperatively were calculated between groups.

Results: Median age at implantation was 11.9 years (IQR 10.2-15.1). Mean preoperative, unaided PTA AC and PTA BC were 71.4 dB (SD 19.5) and 13.7 (SD 12.9). Average aided thresholds at 3 months for 52 patients (59 implants) and >1 year for 14 patients (15 implants) postoperatively were 23.1 dB (SD 6.0) vs 18.3 dB (SD 7.1), mean FG was 46.8 dB (SD 18.0) vs 51.2 (SD 18.9), and mean EG was -10.9 dB (SD 1.5) vs -8.8 dB (SD 3.4) Average 3-month aided thresholds for the Osia®2 vs the BCI 602 were 21.4 dB (SD 5.1) vs 28.8 dB (SD 5.4 dB) (P < .01), but mean 3-month FGs and EGs were non-significant (P=.51, P=.77). Mean follow-up time was 14.6 months (SD 11.1).

Conclusions: In our study, children age 5-18 years with various types of hearing loss received significant, comparable audiologic gain with the BCI 602 and the Osia®2 implants. Audiometric endpoints at >12 months after surgery were comparable to those at 3 months postoperatively. To our knowledge, this is the largest pediatric cohort in the United States to have undergone active transcutaneous bone conduction implantation. Study strengths include prospective collection of patients. Limitations include overall retrospective design and a relatively smaller > 1 year follow-up cohort.