Bone Conduction Implants Research Articles

Outcomes with transcutaneous bone conduction implants in patients with mixed hearing loss

Outcomes with transcutaneous bone conduction implants in patients with mixed hearing loss

Audiological and Subjective Benefits in a Child with Microtia and Atresia After Sequential Bilateral Implantation with Active Bone Conduction Devices: A Case Study

Background: With bilateral hearing loss, the main problems for the patient are speech understanding in noise and, especially in asymmetrical hearing loss, an inability to correctly localize sound sources. There are multiple methods of treatment and rehabilitation for people with conductive hearing loss, and one of them is to use an active bone conduction implant. This case study is designed to evaluate the auditory benefits and sound localization accuracy with active bilateral bone conduction implants—in comparison to unilateral ones—in a patient with congenital bilateral conductive hearing loss caused by a congenital malformation. We assess subjective and audiological benefits (functional, directional hearing, speech comprehension in quiet and noise). Case report: This study describes the results in a 15-year-old patient with bilateral congenital malformation of the outer ears and associated conductive hearing loss who was treated with two Bonebridge active bone conduction implants. Speech recognition ability, hearing thresholds, and sound localization were tested under three conditions: unaided, unilateral on the right-side, and bilateral on both sides. The patient filled in an Abbreviated Profile of Hearing Aid Benefit questionnaire (APHAB) to evaluate limitations in daily life caused by hearing impairment. The results show an improvement in free-field hearing thresholds and the ability to discriminate speech, both in quiet and in noise after implantation. Subjectively, the patient had significantly fewer problems with two implants than with one (or with no implant) in terms of hearing in everyday situations. Conclusions: Unilateral use of the Bonebridge device in a patient with congenital bilateral conductive hearing loss did not provide full benefits. However, bilateral implantation improved speech understanding in noise and sound localization.

Sound Localization in Active Transcutaneous Bone Conduction Implant Users with Single-Sided Deafness.

Evaluate sound localization accuracy of subjects with single-sided deafness (SSD) with active transcutaneous bone conduction implants (atBCIs). Prospective case-control study. Tertiary referral center. Ten SSD patients (with ATBCIS) and 10 controls. Localization was assessed in a semianechoic chamber using a 24-speaker array. Stimuli included broadband noise (BBN) and narrowband noise (NBN). Perceived stimulus angle was recorded and compared with presented location. Statistical analyses were performed using ANOVA and Wilcoxon rank sum tests. The primary outcome measures were as follows: 1) mean angular error (MAE) error (°) and regression slope and 2) subjective benefit assessment (Speech Spatial Qualities questionnaire). Subjects with SSD demonstrated worse localization by MAE and regression slope compared with controls for both broadband noise (p < 0.0001) and narrowband noise at 500 Hz and 1000 kHz (p < 0.0001). There was no statistically significant difference (p = 0.1090) in slope between all groups at 4000 Hz. There was no significant difference in slope or MAE aided compared with unaided. Localization ability varied widely within the SSD cohort, with some individuals showing some ability in the unaided condition, best at 4000 Hz. Although SSQ confirmed particular difficulty in the spatial hearing domain, all domains improved with device use. Localization ability for individuals with SSD falls into a somewhat bimodal distribution. Some have fair localization, particularly at high frequencies, that is preserved but not improved with the atBCI. Others have minimal to no localization ability at any frequency, with no apparent device benefit.

Feasibility and Outcomes of an Active Osseointegrated Bone Conduction Implant in Children as Young as 5 Years of Age.

This study reviews the feasibility of implanting active osseointegrated bone conduction devices in young children, below the prior age for FDA indication (<12 years), which has recently been reduced to 5 years. Outcomes included differences in adverse event rates and operative time between two groups (<12 and 12 years or older). This study is a retrospective review of children receiving active osseointegrated bone conduction devices at a tertiary referral center academic hospital. One hundred and twenty-four children received 135 active osseointegrated bone conduction devices (May 2018-March 2024). Of 135 devices, 77 (57%) were in children <12 years (mean age (SD) = 7.9 (2.0) years, range = 4.9-11.9 years) and 58 (43%) were in 12 years or older (mean age (SD) = 15.1 (1.7) years, range = 12-18 years). Adverse events were significantly higher in the older group, occurring in 8 (10%) of 77 devices in children <12 years and 15 (26%) of 58 devices in children 12 years and older (26%) (Fisher's exact test = 0.0217 at p < 0.05). Major adverse events occurred in 5/124 (4%) patients, with 2 in patients <12 years (2/73, 3%) and 3 in children 12 and older (3/51, 6%). The proportion of major events between groups was not significantly different (Fisher's exact test = 0.4, p < 0.05). Mean surgical time was significantly less (t = -2.8799, df = 120.26, p = 0.005) in the children <12 years (mean (SD) = 66.5 (22.4) min) compared to those 12 and over (mean (SD) = 78.32 (23.1) min). Implantation of active osseointegrated bone conduction devices is feasible in children as young as 5 years and demonstrates low rates of complication. Further miniaturization may allow even earlier safe intervention.

Tinnitus reduction after active bone-conduction implantation in patients with single-sided deafness: a prospective multicenter study.

Single-sided deafness (SSD) presents significant challenges for patients, including compromised sound localization, reduced speech recognition, and often, tinnitus. These issues are typically addressed using interventions such as cochlear implantation (CI) and bone conduction implant (BCI). However, evidence regarding the efficacy of BCI in reducing tinnitus in SSD patients remains limited. This study explored the ability of a novel active transcutaneous BCI (Bonebridge BCI602) to alleviate tinnitus in SSD patients. Prospective cohort multicenter study. Tertiary referral hospitals. A prospective multicenter study of 30 SSD patients was conducted. The patients were divided into two groups: those with (n = 19) and without (n = 11) tinnitus. Audiometric assessments, subjective questionnaires including the Abbreviated Profile of Hearing Aid Benefit (APHAB) and the Bern Benefit in Single-Sided Deafness (BBSS), and tinnitus evaluations with the Tinnitus Handicap Inventory (THI) and tinnitogram were conducted before and after BCI surgery. THI scores after surgery were significantly reduced in SSD patients with tinnitus. Subjective satisfaction improved in both the tinnitus and non-tinnitus groups; however, the former group exhibited a significantly greater improvement in the APHAB questionnaire score. According to tinnitograms, the loudness of tinnitus decreased, particularly in patients with ipsilateral tinnitus. Patients with residual hearing had greater reductions in their THI scores. However, three patients without residual hearing had a relative worsening of tinnitus after surgery. The Bonebridge BCI602 effectively reduced tinnitus in SSD patients, particularly in those with residual hearing. Subjective satisfaction improved in both the tinnitus and non-tinnitus groups. These findings demonstrate the therapeutic potential of BCI for managing SSD and associated tinnitus.

A piezoelectric transducer for bone conduction implants designed using finite element analysis

AbstractThis study describes the design of a transducer for bone conduction implants that combines a piezoelectric element and a displacement amplifier. To develop a displacement amplifier with the maximum possible amplification ratio, theoretical analysis was performed to derive the parameters that affect the amplification ratio. Parametric sweep analysis was conducted to calculate the amplification ratio according to changes in the various parameters. The resulting optimal displacement amplifier afforded the maximum amplification ratio when the beam thickness, depth, inclination angle, and length were 0.15 mm, 1.2 mm, 6.5°, and 4 mm, respectively. The displacement amplifier with these optimal parameter values amplified the piezoelectric element displacement by approximately 7.7‐fold. Frequency characteristic analysis by weight was performed to derive a mechanical resonance location with frequency characteristics that appropriately compensated for hearing loss. As a result of this analysis, when a weight of 0.7 g was applied to the displacement amplifier, the mechanical resonance was that required for bone conduction implant transducers.

Staged implantation of active transcutaneous bone conduction hearing devices (BCHD) after explantation of older generation bone anchored hearing aids (BAHAs): Surgical outcomes and approach to management

PurposeTo evaluate outcomes following explantation of percutaneous or transcutaneous bone conduction implants (pBCIs or tBCIs) and subsequent implantation of transcutaneous active bone conduction hearing devices (BCHDs); to provide guidance regarding staging of surgery and adjunctive procedures. Materials and methodsRetrospective chart review of eight adult subjects (ten ears) with pBCIs or tBCIs who underwent explantation of their device and subsequent implantation with a BCHD [MED-EL BONEBRIDGE™ (n = 7, 70 %) or Cochlear™ Osia® (n = 3, 30 %)]. ResultsReasons for pBCI or tBCI explantation were pain (60 %, 6/10), infection (60 %, 6/10), skin overgrowth (50 %, 5/10), and inability to obtain new processors (20 %, 2/10). Median time between pBCI or tBCI removal and BCHD staged implant was 4.7 (IQR 2.2–8.1) months. Two subjects developed complications following BCHD implantation. One had a persistent wound overlying the osseointegrated screw after removal of the pBCI abutment, requiring removal and temporalis rotational flap. Staged Osia® implantation was performed, but ultimately wound dehiscence developed over the device. The second subject experienced an infection after BONEBRIDGE™ implantation (32 days after pBCI explant), necessitating washout and treatment with intravenous antibiotics. There was subsequent device failure. ConclusionThe transition from a pBCI or tBCI to a novel transcutaneous device is nuanced. Staged pBCI or tBCI explantation and novel BCHD implantation with sufficient time for wound healing is vital. Adjunctive procedures to augment soft tissue in cases of prior attenuation may be required to avoid complications with larger internal devices.

Binaural hearing in monaural conductive or mixed hearing loss fitted with unilateral Bonebridge.

To determine the benefits of binaural hearing rehabilitation in patients with monaural conductive or mixed hearing loss treated with a unilateral bone conduction implant (BCI). This monocentric study includes 7 patients with monaural conductive or mixed hearing loss who underwent surgical implantation of a unilateral BCI (Bonebridge, Med-El). An ITA Matrix test was performed by each patient included in the study - without and with the BCI and in three different settings - to determine the summation effect, squelch effect and head shadow effect. Subjective hearing benefits were assessed using the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire. The difference in signal to noise ratio of patients without and with BCI was 0.79 dB in the summation setting (p < 0.05), 4.62 dB in the head shadow setting (p < 0.05) and 1.53 dB (p = 0.063) in the squelch setting. The APHAB questionnaire revealed a subjective discomfort in the presence of unexpected sounds in patients using a unilateral BCI (aversiveness score) compared to the same environmental situations without BCI, with a mean discomfort score of 69.00% (SD ± 21.24%) with monaural BCI versus 25.67% (SD ± 16.70%) without BCI (difference: -43.33%, p < 0.05). In terms of global score, patients wearing a unilateral Bonebridge implant did not show any significant differences compared to those without hearing aid (difference: -4.00%, p = 0.310). Our study shows that the use of a unilateral BCI in patients affected by monaural conductive or mixed hearing loss can improve speech perception under noise conditions due to the summation effect and to the decrease of the head shadow effect. However, since monaural BCIs might lead to discomfort under noise conditions in some subjects, a pre-operative assessment of the possible individual benefit of a monaural BCI should be carried out in patients affected by unilateral conductive or mixed hearing loss in order to investigate the possible additional effect of the fitting of hearing aids.

Early Results With the New Active Bone-Conduction Hearing Implant: A Systematic Review and Meta-Analysis.

The bone conduction implant (BCI) 602 is a new transcutaneous BCI with smaller dimensions. However, limited patient numbers restrict the statistical power and generalizability of the current studies. The present systematic review and meta-analysis summarize early audiological and medical outcomes of adult and pediatric patients implanted with the BCI 602 due to mixed or conductive hearing loss. Following the Preferred Reporting items for Systematic Reviews and Meta-analyses guidelines, 108 studies were reviewed, and 6 (5.6%) were included in the meta-analysis. The data on study and patient characteristics, surgical outcomes, and audiological test results were extracted from each article. Meta-analysis employed the fixed-effect and random-effects models to analyze the mean differences (MDs) between pre- and postoperative performances. In total, 116 patients were evaluated, including 64 (55%) adult and 52 (45%) pediatric patients. No intraoperative adverse events were reported, while postoperative complications were reported in 2(3.1%) adult and 2 (3.8%) pediatric patients. Studies consistently showed significant improvements in audiological outcomes, quality of life, and sound localization in the aided condition. In the meta-analysis, we observed a significant difference in the unaided compared to the aided condition in sound field thresholds (n = 112; MD, -27.05 dB; P < 0.01), signal-to-noise ratio (n = 96; MD, -6.35 dB; P < 0.01), and word recognition scores (n = 96; MD, 68.89%; P < 0.01). The implantation of the BCI 602 was associated with minimal surgical complications and excellent audiological outcomes for both the pediatric and the adult cohort. Therefore, our analysis indicates a high level of safety and reliability. Further research should focus on direct comparisons with other BCIs and long-term functional outcomes.

Objective preclinical measures for bone conduction implants.

The study evaluates the accuracy of predicting intracochlear pressure during bone conduction stimulation using promontory velocity and ear canal pressure, as less invasive alternatives to intracochlear pressure. Stimulating with a percutaneous bone conduction device implanted in six human cadaveric ears, measurements were taken across various intensities, frequencies, and stimulation positions. Results indicate that intracochlear pressure linearly correlates with ear canal pressure (R2 = 0.43, RMSE = 6.85 dB), and promontory velocity (R2 = 0.47, RMSE = 6.60 dB). Normalizing data to mitigate the influence of stimulation position leads to a substantial improvement in these correlations. R2 values increased substantially to 0.93 for both the ear canal pressure and the promontory velocity, with RMSE reduced considerably to 2.02 (for ear canal pressure) and 1.94 dB (for promontory velocity). Conclusively, both ear canal pressure and promontory velocity showed potential in predicting intracochlear pressure and the prediction accuracy notably enhanced when accounting for stimulation position. Ultimately, these findings advocate for the continued use of intracochlear pressure measurements to evaluate future bone conduction devices and illuminate the role of stimulation position in influencing the dynamics of bone conduction pathways.

Active Bone Conduction Implant and Adhesive Bone Conduction Device: A Comparison of Audiological Performance and Subjective Satisfaction.

Introduction Atresia of the external auditory canal affects 1 in every 10 thousand to 20 thousand live births, with a much higher prevalence in Latin America, at 5 to 21 out of every 10 thousand newborns. The treatment involves esthetic and functional aspects. Regarding the functional treatment, there are surgical and nonsurgical alternatives like spectacle frames and rigid and softband systems. Active transcutaneous bone conduction implants (BCIs) achieve good sound transmission and directly stimulate the bone. Objective To assess the audiological performance and subjective satisfaction of children implanted with an active transcutaneous BCI for more than one year and to compare the outcomes with a nonsurgical adhesive bone conduction device (aBCD) in the same users. Methods The present is a prospective, multicentric study. The audiological performance was evaluated at 1, 6, and 12 months postactivation, and after a 1-month trial with the nonsurgical device. Results Ten patients completed all tests. The 4-frequency pure-tone average (4PTA) in the unaided condition was of 65 dB HL, which improved significantly to 20 dB HL after using the BCI for 12 months. The speech recognition in quiet in the unaided condition was of 33% on average, which improved significantly, to 99% with the BCI, and to 91% with the aBCD. Conclusion The aBCD demonstrated sufficient hearing improvement and subjective satisfaction; thus, it is a good solution for hearing rehabilitation if surgery is not desired or not possible. If surgery is an option, the BCI is the superior device in terms of hearing outcomes, particularly background noise and subjective satisfaction.

Development and validation of a surgical planning tool for bone-conduction implants

BackgroundThe BONEBRIDGE® (Med-El GmbH) is a bone-conduction device comprising an external audio processor and an internal Bone Conduction-Floating Mass Transducer (BC-FMT) surgically anchored to the temporal bone. Due to the implant's size, its placement may be challenging in certain anatomies, necessitating thorough surgical planning. Manual planning methods are laborious, time-intensive, and prone to errors. This study aimed to develop and validate an automated algorithm for determining skull thickness, aiding in the surgical planning of the BONEBRIDGE and other devices requiring similar bone thickness estimations. Materials and methodsTwelve cadaveric temporal bones underwent clinical computed tomography (CT). A custom Python algorithm was developed to automatically segment bone from soft tissue, generate 3D models, and perform ray-tracing to estimate bone thickness. Two thickness colormaps were generated for each sample: the cortical thickness to the first air cell and the total thickness down to the dura. The algorithm was validated against expert manual measurements to achieve consensus interpretation. ResultsThe algorithm estimated bone-to-air thicknesses (mean = 4.7 mm, 95% Confidence Interval [CI] of 4.3–5.0 mm) that closely matched the expert measurements (mean = 4.7 mm, CI of 4.4–5.0 mm), with a mean absolute difference (MAD) of 0.3 mm. Similarly, the algorithm's estimations to the dura (6.0 mm, CI of 5.4–6.5 mm) were comparable to the expert markings (5.9 mm, CI of 5.4–6.5 mm), with a MAD of 0.3 mm. ConclusionsThe first automated algorithm to calculate skull thickness to both the air cells and dura in the temporal bone was developed. Colormaps were optimized to aid with the surgical planning of BONEBRIDGE implantation, however the tool can be generalized to aid in the surgical planning of any bone thickness application. The tool was published as a freely available extension to the open-source 3D Slicer software program (www.slicer.org).

Bone Conduction Implants: Comparative of Audiometric Results and Quality-of-Life Bonebridge® versus Osia®

Introduction: Bone conduction implants have been indicated for patients with conductive hearing loss, mixed hearing loss, and even profound unilateral sensorineural hearing loss. With the introduction of Bonebridge®, new transcutaneous implant options emerged. The latest is Osia®, a direct-drive variant or active systems, where the implant directly generates and applies vibration to the bone. Materials and Methods: Retrospective study of two cohorts of patients treated with active bone conduction implants at a single center, one with the Bonebridge® device and the other with Osia®. Outcomes: Fourteen patients were included, seven in each group (n = 14). The Bonebridge® group showed an average hearing gain in tonal intelligibility thresholds of 32.43 ± 21.39 dB and a gain in the average intelligibility threshold (with 50% discrimination) of 26.29 ± 19.10 dB. In the Osia® group, there was a gain in average tonal thresholds of 41.49 ± 14.16 dB and 23.72 ± 6.98 dB in average intelligibility thresholds. Both devices contributed to improvements in patients’ quality of life, as assessed with APHAB in all the variables studied in the test. Both devices offer rehabilitation for hearing loss as an alternative to hearing aids. The Osia® system shows statistically significant (p < 0.05) improvements in mid and high frequencies, but Bonebridge® slightly outperforms in speech understanding at 50%. Differences in average tonal thresholds and quality of life are not statistically significant. Conclusions: While auditory improvement is observed postimplantation, other aspects, such as intelligibility thresholds and quality of life, lack statistical significance. Given the limited experience with Osia® and the small sample size, the choice of the device should be personalized. Although the literature is inconsistent due to small sample sizes and variable approaches, some studies suggest potential advantages of the Osia® system, especially in speech comprehension in different environments and greater hearing gain compared to Bonebridge®.

Transitioning from Cochlear&amp;trade; Baha&amp;reg; to Bilateral CochlearTM Osia&amp;reg;: Two Case Reports

&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Bone conduction implants are essential devices for enhancing auditory perception in patients with conductive or mixed hearing loss, particularly when conventional hearing aids fail to meet their needs. The advancement of bone conduction technology has led to improved patient outcomes and quality of life.&lt;br /&gt;&lt;strong&gt;Case Presentation:&lt;/strong&gt; This case series presents two case reports detailing the transition from unilateral BAHA Attract&amp;reg;&lt;br /&gt;and bilateral BAHA Connect&amp;reg;systems to bilateral Osia&amp;reg;implants. These transitions address the significant limitations of traditional BAHA systems, such as skin complications and sound attenuation. The transition involved careful planning and assessment, ensuring that the new Osia&amp;reg;implants were suitable for their individual auditory profiles. Post-implantation evaluations indicated a marked improvement in auditory performance and overall satisfaction.&lt;br /&gt;&lt;strong&gt;Conclusion:&lt;/strong&gt; The case reports demonstrate the superior performance of Osia&amp;reg;implants, highlighting their potential to reduce complications and significantly improve auditory outcomes. These findings also demonstrate the clinical benefits and growing relevance of transitioning from BAHA to Osia&amp;reg;systems for patients with complex auditory needs.&amp;nbsp;&lt;/p&gt;

Evaluating temporal bone column density for optimized bone conduction implant placement

IntroductionAn optimal placement of bone conduction implants can provide more efficient mechanical transmission to the cochlea if placed in regions with greater bone column density. The aim of this study was to test this hypothesis and to determine the clinical potential of preoperative bone column density assessment for optimal implant placement.MethodsFive complete cadaver heads were scanned with quantitative computed tomography imaging to create topographic maps of bone density based on the column density index (CODI). Laser Doppler vibrometry was used to measure cochlear promontory acceleration under bone conduction stimulation in different locations on the temporal bone, using a bone-anchored hearing aid transducer at frequencies ranging from 355 Hz to 10 kHz.ResultsWe found a statistically significant association between CODI levels and the accelerance of the cochlear promontory throughout the frequency spectrum, with an average increase of 0.6 dB per unit of CODI. The distance between the transducer and the cochlear promontory had no statistically significant effect on the overall spectrum.DiscussionWe highlight the importance of bone column density in relation to the mechanical transmission efficiency of bone conduction implants. It may be worthwhile to consider column density in preoperative planning in clinical practice.

Prediction of postoperative speech comprehension with the transcutaneous partially implantable bone conduction hearing system Osia®.

The active transcutaneous, partially implantable osseointegrated bone conduction system Cochlear™ Osia® (Cochlear, Sydney, Australia) has been approved for use in German-speaking countries since April 2021. The Osia is indicated for patients either having conductive (CHL) or mixed hearing loss (MHL) with an average bone conduction (BC) hearing loss of 55 dB HL or less, or having single-sided deafness (SSD). The aim of this retrospective study was to investigate the prediction of postoperative speech recognition with Osia® and to evaluate the speech recognition of patients with MHL and in particular an aided dynamic range of less than 30 dB with Osia®. Between 2017 and 2022, 29adult patients were fitted with the Osia®, 10patients (11ears) with CHL and 19patients (25ears) with MHL. MHL was subdivided into two groups: MHL‑I with four-frequency pure-tone average in BC (BC-4PTA) ≥ 20 dB HL and < 40 dB HL (n = 15patients; 20ears) vs. MHL-II with BC-4PTA ≥ 40 dB HL (n = 4patients; 5ears). All patients tested abone conduction hearing device on asoftband preoperatively. Speech intelligibility in quiet was assessed preoperatively using the Freiburg monosyllabic test in unaided condition, with the trial BCHD preoperatively and with Osia® postoperatively with Osia®. The maximum word recognition score (mWRS) unaided and the word recognition score (WRS) with the test system at 65 dB SPL were correlated with the postoperative WRS with Osia® at 65 dB SPL. Preoperative prediction of postoperative outcome with Osia® was better using the mWRS than by the WRS at 65 dB SPL with the test device on the softband. Postoperative WRS was most predictive for patients with CHL and less predictable for patients with mixed hearing loss with BC-4PTA ≥ 40 dB HL. For the test device on a softband, the achievable outcome tended to a minimum, with the mWRS tending to predict the realistically achievable outcome. Osia® can be used for the treatment of CHL and MHL within the indication limits. The average preoperative bone conduction hearing threshold also provides an approximate estimate of the postoperative WRS with Osia®, for which the most accurate prediction is obtained using the preoperative mWRS. Prediction accuracy decreases from aBC-4PTA of ≥ 40 dB HL.

A Novel Surgical Technique for BAHA&lt;sup&gt;®&lt;/sup&gt; Attract Implantation

An implantable bone conduction hearing aid is a device that assists hearing by transmitting sound vibration through the bone. It is suitable not only for patients with conductive hearing loss and congenital external aural atresia but also for those with unilateral hearing loss, chronic otitis media, or patients whose normal structure has been destroyed due to previous surgery. In this paper, we introduce a novel surgical technique for an implantable bone conduction hearing aid (BAHA&lt;sup&gt;®&lt;/sup&gt; Attract) that can be performed through minimal incision in a short time under local anesthesia based on accurate anatomical characteristics. We believe this novel technique could provide convenience for patients and surgeons. Additionally, through this technique, we can expect that various types of implantable bone conduction hearing aids that function effectively and safely can be provided for patients.

Lumped element models of sound conduction in the human ear: A systematic review.

Lumped element models facilitate investigating the fundamental mechanisms of human ear sound conduction. This systematic review aims to guide researchers to the optimal model for the investigated parameters. For this purpose, the literature was reviewed up to 12 July 2023, according to the PRISMA guidelines. Seven models are included via database searching, and another 19 via cross-referencing. The quality of the models is assessed by comparing the predicted middle ear transfer function, the tympanic membrane impedance, the energy reflectance, and the intracochlear pressures (ICPs) (scala vestibuli, scala tympani, and differential) with experimental data. Regarding air conduction (AC), the models characterize the pathway from the outer to the inner ear and accurately predict all six aforementioned parameters. This contrasts with the few existing bone conduction (BC) models that simulate only a part of the ear. In addition, these models excel at predicting one observable parameter, namely, ICP. Thus, a model that simulates BC from the coupling site to the inner ear is still lacking and would increase insights into the human ear sound conduction. Last, this review provides insights and recommendations to determine the appropriate model for AC and BC implants, which is highly relevant for future clinical applications.

Prediction of speech understanding with the transcutaneous partially implantable bone conduction hearing system Osia®. German Version

The active transcutaneous, partially implantable osseointegrated bone conduction system Cochlear™ Osia® (Cochlear, Sydney, Australia) has been approved for use in German-speaking countries since April 2021. The Osia is indicated for patients with conductive (CHL) or mixed hearing loss (MHL) with an average bone conduction (BC) hearing loss of 55 dB or less, or with single-sided deafness (SSD). The aim of this retrospective study was to investigate the prediction of postoperative speech recognition with Osia and to evaluate the speech recognition of patients with MHL and an aided dynamic range of less than 30 dB with Osia. Between 2017 and 2022, 29adult patients were fitted with the Osia, 10patients (11ears) with CHL and 19patients (21ears) with MHL. MHL was subdivided into two groups: MHL‑I with four-frequency pure-tone average in BC (BC-4PTA) ≥ 20 dB HL and < 40 dB HL (n = 15patients; 20ears) vs. MHL-II with BC-4PTA ≥ 40 dB HL (n = 4patients; 5ears). All patients tested abone conduction hearing device on asoftband preoperatively. Speech intelligibility in quiet was assessed preoperatively using the Freiburg monosyllabic test unaided and with the test system and postoperatively with Osia. The maximum monosyllabic score (mEV) unaided and the monosyllabic score with the test system at 65 dB SPL were correlated with the postoperative monosyllabic score with Osia at 65 dB SPL. Preoperative prediction of postoperative outcome with Osia was better using the mEV than the EV at 65 dB SPL with the test device on the softband. Postoperative EV was most predictive for patients with CHL and least predictive for patients with mixed hearing loss with 4PTA BC ≥ 40 dB HL. For the test device at softband, results tended to show the minimum achievable outcome and the mEV tended to predict the realistically achievable outcome. Osia can be used for the treatment of CHL and MHL within the indication limits. The average preoperative bone conduction hearing threshold also provides an approximate estimate of the postoperative EV with Osia, for which the most accurate prediction is obtained using the preoperative mEV. Prediction accuracy decreases from aBC-4PTA of ≥ 40 dB.

Magnetic Resonance Imaging Artifact Associated With Transcutaneous Bone Conduction Implants: Cholesteatoma and Vestibular Schwannoma Surveillance.

To evaluate the magnetic resonance (MR) image artifact and image distortion associated with the two transcutaneous bone conduction implants currently available in the United States. Cadaveric study. Two cadaveric head specimens (1 male, 1 female) were unilaterally implanted according to manufacturer guidelines and underwent MR imaging (General Electric and Siemens 1.5 T scanners) under the following device conditions: (1) no device, (2) Cochlear Osia with magnet and headwrap, (3) Cochlear Osia without magnet, and (4) MED-EL Bonebridge with magnet. Maximum metal mitigation techniques were employed in all conditions, and identical sequences were obtained. Blinded image scoring (diagnostic vs nondiagnostic image) was performed by experienced neuroradiologists according to anatomical subsites. All device conditions produced artifact and image distortion. The Osia with magnet produced diagnostic T1- and T2-weighted images of the ipsilateral temporal bone, however, non-echo planar imaging diffusion-weighted imaging (DWI) was nondiagnostic. The Osia without magnet scanned on the Siemens MR imaging demonstrated the least amount of artifact and was the only condition that allowed for diagnostic imaging of the ipsilateral temporal bone on DWI. The Bonebridge produced a large area of artifact and distortion with the involvement of the ipsilateral and contralateral temporal bones. In summary, of the three device conditions (Osia with magnet, Osia without magnet, and Bonebridge), Osia without magnet offered the least amount of artifact and distortion and was the only condition in which diagnostic DWI was available for the middle ear and mastoid regions on the Siemens MR imaging scanner.