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

An international multicentre, open, comparative, parallel group, prospective clinical investigation with a single 5 year follow up visit.

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.

The product was the standard titanium implant and abutment in the Baha system developed by Cochlear Bone Anchored Solutions AB. The implant is 3.75 mm wide and 4.0 mm long

The product was the novel titanium implant and abutment for the Baha system developed by Cochlear Bone Anchored Solutions AB. The novel implant is 4.5 mm wide and 4.0 mm long.

The Novel Implant BI300 was the new titanium implant and abutment for the Baha system developed by Cochlear Bone Anchored Solutions AB. The novel implant is 4.5 mm wide and 4.0 mm long.

The Standard Implant BI300 was the standard titanium implant and abutment in the Baha system developed by Cochlear Bone Anchored Solutions AB. The implant is 3.75 mm wide and 4.0 mm long

To show superiority of the novel implant compared to standard implants regarding stability of the implants measured as ISQ values at the abutment level. The ISQ value ranges from 1 to 100, the higher ISQ value, the higher the implant stabilty. Mean AUC 0-60 months ISQ represents a weighted average of the implant stability during the 60 months from start of the CAG5173 study to the measurement in this study CBAS5562. The ISQ 5 years value represents the single ISQ measurment at 5 years.

To compare the long term survival of the novel implant and abutment and the standard implant and abutment in the Baha system. All patients will be asked if they have experienced any implant osseointegration problems which would have made the implant to get loose. The time from implant implantation until implant loss or removal will be collected. In case of implant removal, reason for removal shall be recorded.

To evaluate the status of the soft tissue at the implant site. The scale Holgers Index 4 is designed to capture signs and symptoms of inflammation or infection at the site of implantation. The scale should be completed at the visit. The scale consists of the following steps: 0. No irritation. Epidermal debris removed, if present Slight redness. Local temporary treatment, if needed Red and slightly moist tissue. No granulation formation, local treatment and extra controls as indicated Reddish and moist; sometimes granulations tissue, revision surgery is indicated Removal of the abutment/implant necessary due to infection R. Removal of abutment/implant for reasons not related to skin problems

Inclusion Criteria: Participated in the CAG5173 investigation Signed informed consent Exclusion Criteria: Unable to follow investigational procedure Any factor, at the discretion of the investigator, that is considered to contraindicate participation