Long Term Stability, Survival and Tolerability of a (Novel) Baha® Implant System

Two implant products, the standard implant and abutment and the novel implant and abutment, both developed by Cochlear Bone Anchored Solutions AB were tested in the CAG5173 clinical investigation that was completed in December 2012. The primary objective was to show superiority of the novel implant compared to standard implant in terms of implant stability quotient (ISQ) as as measured by resonance frequency analysis1. Results after 6 and 36 months after implantation showed that the new design, the novel implant and abutment, provided statistically significantly higher stability at the time of insertion and over time compared to the standard Baha implant2,3,4. In the investigation, sound processor fitting was performed from 6 weeks post-implantation. No reduction in implant stability following sound processor fitting was recorded, suggesting that it is safe to load the implant 6 weeks after implantation. The investigation also showed improved soft tissue outcomes, in terms of lower Holgers index5 scores for the novel implant and abutment compared to the standard implant and abutment.

After initiation of the 3-year CAG5173 investigation, Cochlear Bone Anchored Solutions AB launched the Cochlear Baha BIA300 Implant and Abutment, which in all critical aspects are identical to the novel implant used in the investigation.

The 36-month visit was the last visit of the investigation. Hence, no further visits were planned or scheduled for the subjects participating in that investigation.participating subjects. It is of clinical and scientific interest to evaluate the clinical performance and safety data of the implants in these subjects after an additional two-year period, in order to gain additional understanding of how implant stability and soft tissue status evolves over time with the two implant and abutment designs, and in order to evaluate long-term implant survival. No randomised controlled investigation of Baha implants with a 5-year follow-up has been conducted to date.

The rationale behind this clinical investigation is to collect long term stability, survival and tolerability data of a novel Baha implant system 5 years after implantation in a population that previously have been followed in a completed controlled investigation during a 3 year period. The collected data will enable comparison with the data gathered in the previous completed CAG5173 clinical investigation.