Learning Objectives: Potential clinical implications of early loading of a bone anchored hearing implant. How to evaluate stability and soft tissue reactions of a bone anchored hearing implant. Results from a clinical study of early loading of a bone anchored hearing implant.
Objectives: To assess implant stability and safety of loading a bone anchored hearing implant one week after surgery. To evaluate post-operative skin complications of a bone anchored hearing implant abutment coated with hydroxyapatite.
Design: Single centre, prospective cohort study of 25 adults with normal skin and bone quality, approved by danish health authorities.
Intervention: Implantation of the Baha BA400 implant system using a linear incision technique without skin thinning. Abutment lengths of 8 mm,10 mm and 12 mm were used.
Outcome measures: Implant Stability Quotient (ISQ) (primary) and soft tissue evaluation (Holgers grade, skin overgrowth, pain, numbness) (secondary) at 0, 7, 14, 30 days and 3, 6 and 12 months.
Results: 25 patients were included, 23 could be followed up for one year. Mean ISQ was increasing with no sign of adverse influence from the early loading. No implants were lost or clinically unstable. Individual ISQ curves fall in two categories: continually increasing ISQ or increasing ISQ with initial dip. 93.8% of all visits resulted in a Holgers Grade 0 or 1. Skin overgrowth occurred in 2.1% of all visits. Pain was none or mild in 97.9% of all visits. For all visits there was no (95.8%) or mild (4.2%) numbness around the implant. Within the first month of follow-up there was a significantly higher score for the Holgers Grade (p = 0.005, Mann-Whitney U-test) and significantly more pain (p = 0.01, Mann-Whitney U-test) compared with the previous generation implant.
Conclusion: Loading of the implant system 1 week after surgery has been successful for 25 patients with normal bone quality followed up for one year. No implants were lost. All individual ISQ were increasing throughout the study period, although some showed an initial ISQ dip. Soft tissue reactions around the hydroxyapatite coated abutment were generally mild and tolerable but elevated in the first month of follow-up compared with the previous generation implant.
