Stability, survival, and tolerability of a 4.5-mm-wide bone-anchored hearing implant: 6-month data from a randomized controlled clinical trial

Abstract

The objective of this study was to compare the stability, survival, and tolerability of 2 percutaneous osseointegrated titanium implants for bone conduction hearing: a 4.5-mm diameter implant (test) and a 3.75-mm diameter implant (control). Fifty-seven adult patients were included in this randomized controlled clinical trial. Sixty implants were allocated in a 2:1 (test–control) ratio. Follow-up visits were scheduled at 7, 14, 21, and 28 days; 6 and 12 weeks; and 6 months. At every visit, implant stability quotient (ISQ) values were recorded by means of resonance frequency analysis (RFA) and skin reactions were evaluated according to the Holgers classification. Implants were loaded with the bone conduction device at 3 weeks. Hearing-related quality of life was evaluated using the Abbreviated Profile of Hearing Aid Benefit (APHAB), the Glasgow Benefit Inventory (GBI), and the Glasgow Health Status Inventory (GHSI). ISQ values were statistically significantly higher for the test implant compared to the control implant. No implants were lost and soft tissue reactions were comparable for both implants. Positive results were reported in the hearing-related quality of life questionnaires. These 6-month results indicate that both implants and their corresponding hearing devices are safe options for hearing rehabilitation in patients with the appropriate indications. Loading at 3 weeks did not affect the stability of either implant.

Controlled Clinical Trial on Bone-anchored Hearing Implants and a Surgical Technique With Soft-tissue Preservation

“…The increased soft tissue reactions should be interpreted with care, and further follow-up is needed to draw conclusions. The number of adverse soft-tissue reactions in the controlgroup (n ¼ 1, 4%), was lower compared with the percentage of adverse soft-tissue reactions in the complete study group from which the current control-group was a subset (5). A pathophysiological hypothesis for the increased soft-tissue reactions could be the result of more free movement of soft-tissue surrounding the abutment, as was described previously by Brånemark and Albrektsson (21).…”

“…The overall thresholds on abutment, which are clinically most relevant given similar hearing thresholds, showed no difference between groups (mean 25. 5 Comparing individual frequency thresholds between the two study groups for the abutment and for the B71 conditions, no significant differences where noticed. In the testband condition a difference was noted at the 1-kHz frequency (mean, 30.2 [SD 12.9] versus 20.8 [SD 14.0], p ¼ 0.028).…”

“…The last 25 patients implanted with a wide implant using the linear incision technique with tissue reduction in a randomized controlled trial comparing wide implants with previous generation implants were asked to participate as controls in the current study (5). Identical implants and abutments were used in both groups and surgeries were performed by the same surgeons.…”

“…When reviewing several frequently used techniques, the linear incision has been shown to be superior in several studies (1)(2)(3). With the linear incision technique, as well as new implant and abutment designs, complications such as implant loss and adverse soft-tissue reactions have decreased to 0 to 4% and 8 to 15% respectively per implant in the adult population (4,5).…”

Percutaneous bone‐anchored hearing system implant survival after 550 primary implant surgeries

“…During the early years of development, implant loss rates may have been higher. In recent years, wider implants have been introduced which increased stability and facilitated the use of longer abutments and possibly early loading. These wider implants may have improved 5‐year survival rates.…”