The Osia System is a transcutaneous bone anchored hearing aid which can be used for the correction of both conductive and sensorineural hearing loss. This video depicts the implantation of the Osia in a pediatric patient with a history of right-sided microtia.
This video depicts the implantation of the Osia System, a transcutaneous bone anchored hearing aid, in a pediatric patient with a history of right sided microtia.
Traditional bone anchored hearing aids (BAHAs) have relied on the percutaneous approach to connect an external sound processor to an osseointegrated screw through a titanium abutment placed in two separate surgeries. The newer transcutaneous approach uses a transducer that is internally implanted in a single surgery and connected via magnetics to an external processor.
The Osia has been officially approved for patients over the age of 12 with either single-sided deafness or bilateral hearing loss. For those patients with bilateral hearing loss, the device is best suited for those with symmetric conductive or mixed hearing loss. Contraindications include insufficient bone quality, chronic vestibular disorders, and skin or scalp conditions that interfere with placement.
Materials and Methods
The Osia was implanted by creating a subperiosteal pocket with a Cochlear Conical Guide Drill with a 3mm spacer.
The patient’s postoperative course was uneventful, and he was discharged on the day of surgery. After three weeks the patient’s incision was cleared, and the external processor was connected and activated. The patient was able to take full advantage of the device just six weeks after the operation.
The Osia and other transcutaneous BAHAs are a safe alternative to percutaneous BAHAs in pediatric patients with conductive hearing loss.
Bone anchored hearing aids (BAHAs) have been used in children for over 30 years, with implantation success rates reaching those of adults for patients over the age of 5 years old.1 Evidence suggests that BAHAs impact both objective measures of hearing, such as hearing in noise, as well as functional outcomes for pediatric patients.2,3 For patients with microtia, BAHAs has been successfully used to improve hearing in both unilateral and bilateral cases of conductive hearing loss.4 While there have been several models of BAHAs, they share the same fundamental design based on a percutaneous approach: an osseointegrated screw, titanium abutment, and external sound processor. The Osia System offers a new design with a transcutaneous approach and a new type of sound processor.
While traditional BAHAs rely on a titanium abutment to connect the osseointegrated screw and sound processor, the Osia’s transducer is implanted completely internally and connected to the processor via magnetics. In addition to the cosmetic benefits of the transcutaneous approach, the Osia can be completely placed in a single surgery rather than the traditional two phase surgery typically required for the osseointegrated version. The Osia’s sound processor uses piezoelectric material and works within a steady-state system, which when combined with the internal transducer provides clearer amplification of higher frequencies.5
Another advantage of the Osia is the versatility of surgical candidates. The Osia System can be safely used in patients over the age of 12 with either single-sided deafness or bilateral hearing loss. The device can be fitted bilaterally for patients with symmetric conductive or mixed hearing loss. Contraindications are similar to those of other BAHAs and include insufficient bone quality, chronic vestibular disorders, and skin or scalp conditions that interfere with implant placement. However, currently the Osia system is only FDA approved for patients over the age of 12.
We present a case of an 18-year-old patient with a history of right sided microtia successfully implanted with an Osia implant.
An 18-year old male with a history of right-sided microtia and atresia presented for discussion of an assistive hearing device. The patient was counseled on available options, including surgical and nonsurgical options, and chose to pursue the Osia after successful use of a soft band BAHA. The patient was sent for audiologic evaluation which showed moderate to severe conductive hearing loss in the right ear and normal hearing in the left ear. Given his age and unilateral hearing loss, the CochlearTM OsiaÒ 2 system was chosen.
Our patient was fitted for the CochlearTM OsiaÒ 2. This system includes both external and internal components. Internally there are two main components: the receiver, which has the internal magnet, and the actuator, the simulator that allows for sound transduction. Externally, the sound processor houses the external magnet, a microphone, and a battery.
Anatomy & Landmarks:
The OS1200 Implant was implanted on behind the patient’s right ear. The patient had a prior microtia repair, and the edge of the OS1200 Implant was placed 10mm from the previous surgical incision (Figure 1).
Set-Up & Procedure:
After induction of anesthesia, the patient’s bed was turned 90 degrees counterclockwise. The Osia system includes a template of the OS1200 for planning the correct position of the implant and this was used to mark the skin for surgery. The edge of the implant was marked 10mm from the previous microtia repair incision (Figure 1). Using a hypodermic needle, the scalp thickness measured and found to be 7mm, less than the recommended 9mm to enable appropriate magnetic connectivity. The location of the BI300 implant was marked with methylene blue through the hole of the actuator in the OS1200 implant template as observed in the video.
Local anesthesia was then injected along the planned incision. Using a 15 blade, the initial incision was made and a posterior pocket for the coil was developed using a combination of blunt dissection and Bovie cautery, as observed in the video (Figure 2). The size and depth of the pocket was measured using the OS1200 Implant template to ensure that the pocket developed would accommodate the implant (Figure 3). Next, a subperiosteal pocket was created for the magnet and the periosteum around the planned BI300 implant location was cleared away using a small cruciate incision. The Cochlear Conical Guide Drill with a 3mm spacer was used to make the incision hole at 2000 rpm. The bottom of the site was then checked for proper bone thickness and found to be sufficient. The spacer was then removed and the hole was drilled to a depth of 3mm. The BI300 Implant was drilled with the Cochlear Conical Guide Drill at 40Ncm (Figure 4).
The bone bed indicator was then rotated clockwise, and any interfering soft tissue was removed. With the BI300 Implant successfully placed, the surgery proceeded with implantation of the OS1200 Implant.
Prior to placing the OS1200 Implant into the soft tissue pocket, the OS1200 Implant fixation screw was fixed to the Implant. The center of the actuator of the OS1200 Implant was then placed on top of the BI300 Implant and the fixation screw was gently hand-tightened using the screwdriver. The screw was then further tightened to 25 Ncm with the machine screwdriver, UniGrip, and the multi-wrench with the ISO adapter, while the actuator was held in the surgeon’s fingers (Figure 5).
With the Cochlear Osia System BI300 and OS1200 implants both in place, attention was turned to skin closure. The skin incision was closed in 2 layers using 4-0 Vicryl for the deep layer with interrupted sutures and 5-0 fast suture for the skin in a running fashion. A Glasscock dressing was then placed over the ear.
The patient was discharged home after the surgery with follow-up planned for 2 weeks post-operatively. The patient was sent home with a 10-day course of cephalexin.
Figures can be found here: https://docs.google.com/document/u/0/d/11KKawAU61cbHy0tNV1nNw5B9QPn3No_Ko44d1lPxuKc/mobilebasic
Surgical recovery in patients should largely be without complications, and our patient reported experiencing only minor muscle cramping near the surgical site. Other complications traditionally seen with BAHA placement are numbness, pain, inflammation or infection at the incision site. Skin complication rates of other BAHAs range from 5-15%.6 The advantage of this surgical procedure with the new Osia device is that the size and material of the processor allow for more stability in osseointegration and a quicker healing time, addressing concerns about both fixture loss and skin complications due to prolonged healing.7 Further, the vibration required for sound conduction does not cause friction on the skin as in prior osseointegrated devices such as a the Baha Attract.
After our patient was evaluated three weeks post-operatively, he was determined to have adequate healing at the surgical site and was cleared to proceed with activation of the Osia Sound Processor. He proceeded to have his device activated three weeks following surgical clearance and was able to take full advantage of his device just six weeks after surgery.
The implantation of the Cochlear Osia System is performed in one surgery, rather than the traditional two-stage surgery commonly performed in the placement of percutaneous BCHD devices in pediatric patients.7 These percutaneous device implant surgeries are performed in two stages to allow for osseointegration of the titanium implant, which typically occurs within 4 to 6 months. Following this period, the titanium abutment is implanted, and the sound processor is connected to the device few weeks after. The advantage of the surgical procedure with the Osia device, and other transcutaneous devices, is that only one surgery is necessary, shortening the time between implantation and utilization of the device.
With transcutaneous devices, the lack of skin-penetrating abutments leads to lower infection rates and potentially lower rates of implant loss.3 With traditional surgery for percutaneous devices, skin inflammation and infections rates near 20% in the pediatric population and 15% in the adult population.8 There have been developments of surgical technique for percutaneous devices, namely the minimally invasive pouch technique, that have reduced those rates and led to reduced loss of devices.9 With transcutaneous devices in adult patients, there reported skin complications rates as low as 1.1%, in which a single patient in the study had mild swelling.10 Another study of patients with transcutaneous devices reported rates of skin complications as 4.6% after 24 months of follow-up.3
Finally, patients who opt for the cochlear Osia System can expect to experience greater speech recognition than with other BAHA devices due to the Osia System’s ability to amplify higher frequencies.2,3
Common pitfalls encountered during Osia implantation derive from issues with bone thickness and skull curvature. Planning to ensure that the device has as flat of a surface as possible after implantation is critical to ensure appropriate conduction. This may require some drilling to flatten the contour of the skull, in particular in pediatric patients. Special care must be taken in those patients with thin bone as well. We recommend beginning with a 3mm bur to ensure that the dura is not violated in these cases.
Utilizing the Cochlear Osia System as a bone conduction hearing implant for pediatric patients with conductive hearing loss can shorten the duration patients need to wait for hearing assistance following implantation, reduce post-operative skin infections, and improve hearing at higher frequencies.
Nothing to disclose
1. Snik FM, Mylanus EAM, Proops DW, et al. Consensus Statements on the BAHA System: Where Do We Stand at Present? Ann Otol Rhinol Laryngol. 2005;114(12_suppl):2-12. doi:10.1177/0003489405114S1201
2. Appachi S, Specht JessicaL, Raol N, et al. Auditory Outcomes with Hearing Rehabilitation in Children with Unilateral Hearing Loss: A Systematic Review. Otolaryngol Neck Surg. 2017;157(4):565-571. doi:10.1177/0194599817726757
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7. Roman S, Nicollas R, Triglia J-M. Practice guidelines for bone-anchored hearing aids in children. Eur Ann Otorhinolaryngol Head Neck Dis. 2011;128(5):253-258. doi:10.1016/j.anorl.2011.04.005
8. Dun CAJ, Faber HT, de Wolf MJF, Mylanus EAM, Cremers CWRJ, Hol MKS. Assessment of more than 1,000 implanted percutaneous bone conduction devices: skin reactions and implant survival. Otol Neurotol Off Publ Am Otol Soc Am Neurotol Soc Eur Acad Otol Neurotol. 2012;33(2):192-198. doi:10.1097/MAO.0b013e318241c0bf
9. Sardiwalla Y, Jufas N, Morris DP. Long term follow-up demonstrating stability and patient satisfaction of minimally invasive punch technique for percutaneous bone anchored hearing devices. J Otolaryngol - Head Neck Surg. 2018;47. doi:10.1186/s40463-018-0316-5
10. Dimitriadis PA, Farr MR, Allam A, Ray J. Three year experience with the cochlear BAHA attract implant: a systematic review of the literature. BMC Ear Nose Throat Disord. 2016;16. doi:10.1186/s12901-016-0033-5