Background: Conductive or mixed hearing loss with a normal tympanic membrane is most often attributed to otosclerosis. However, primary malleus fixation also known as House or Goodhill syndrome is a rare differential diagnosis that can mimic stapes fixation and fundamentally alters surgical management [1 4]. Case presentation: A 67-year-old man presented with long-standing, bilateral hypoacusis, more pronounced on the right side. Otoscopy was normal. Audiometry showed bilateral mixed hearing loss with a mean air bone gap (ABG) of about 30 dB, without a Carhart notch. The initial high-resolution temporal bone CT (HRCT) appeared normal. Endoscopic middle-ear exploration was undertaken for presumed otosclerosis. Intraoperatively, the handle of the malleus was immobile, and stapes palpation did not show the typical fixity of otosclerosis. The procedure was halted for diagnostic reassessment. Re-evaluation of the HRCT revealed ossification of the malleus suspensory ligament, confirming House syndrome [2,5]. A revision transcanal endoscopic ossiculoplasty was then performed, including uncudo-stapedial disarticulation, section of the incus long process, and insertion of a partial ossicular replacement prosthesis (PORP) between the malleus and stapes head. Postoperative recovery was uneventful, with partial ABG closure and significant functional improvement.

To review the literature regarding malleostapedotomy as primary or revision surgery in patients with stapes fixation, to point out the state of the art regarding indications, techniques and outcomes of this procedure. PubMed, CINAHL and Cochrane databases were screened following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Clinical studies describing malleostapedotomy in patients with stapes fixation were included in this Systematic Review. Data about indications, intraoperative findings, features of the prostheses and audiological results were recorded. A total of 25 articles and 632 ears that underwent malleostapedotomy were included in the analysis. This technique has been employed for both primary and revision surgeries, evolving over time alongside advancements in the prostheses used. Revision otosclerosis surgery was identified as the most common surgery necessitating malleostapedotomy. Among the cases, 44.8% achieved ABG closure within 10 dB, while 84.9% achieved ABG closure within 20 dB. Malleostapedotomy is a safe and valid surgical technique that can be performed when incus anchoring stapedoplasty is not feasible.

Air conduction and bone conduction thresholds in audiograms provide clinically useful information. However, whether bone conduction audiograms can help distinguish between different conductive hearing disorders remains unestablished. This retrospective case-control study included patients with hearing loss (surgically-confirmed ossicular sclerosis, ossicular discontinuity or tympanic membrane perforation) and a group of people with normal hearing (Jikei University School of Medicine, Tokyo, Japan). Data were collected between November 30, 2017 and December 30, 2022. Bone conduction threshold patterns (pure tone audiometry) were compared between groups. All experiments were performed in accordance with the relevant guidelines and regulations. Ossicular fixation was associated with a dip at 2 kHz (57.8% of cases) in the bone conduction thresholds, whereas ossicular discontinuity showed a steep downslope of > 10 dB HL from 1 kHz to 3 kHz (75.0% of cases) with a tendency for a dip at 3 kHz (56.3% of cases). For patients with ossicular fixation, the probability of malleus or incus fixation was higher when the bone conduction thresholds at low frequencies (≤ 1 kHz) exhibited an upslope, whereas the probability of stapes fixation was higher when the pattern was a downslope (likelihood ratio = 4.9, P < 0.001). For patients with ossicular discontinuity, the probability of incomplete discontinuity was higher when the low-frequency bone conduction thresholds sloped upward, whereas a downslope was associated with a higher probability of complete discontinuity (likelihood ratio = 6.6, P = 0.018). Analysis of the pattern of the bone conduction thresholds might facilitate the preoperative diagnosis of ossicular sclerosis or ossicular discontinuity in patients with conductive hearing loss.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-19019-1.

Conductive hearing loss requires the surgeon to evaluate ossicular movement to plan and execute surgery. An objective assessment of the ossicular chain with laser vibrometry would likely improve the results of ossiculoplasty. Minimally invasive intraoperative laser vibrometry (MIVIB), a fast and accurate technique, using a continuous time-domain signal that stimulates the Med-El FMT transducer attached to the malleus in a temporal bone model, was used to evaluate artificial fixation of the ossicular chain. Through this analysis method, differing incus velocity responses were seen between simulated single and multiple ossicle fixations in frequencies above 1000 Hz (</> -25 dB respectively). The incus-umbo velocity ratio was shown to detect stapes fixation in both multiple and single ossicle fixations (> -20 and > -10 dB, respectively) highlighting the importance of determining between single and multiple ossicle fixations first. MIVIB provides an objective assessment of the ossicular chain to identify specific fixations and therefore assist the surgeon in improving surgical outcomes.

To develop and preliminarily validate a 3D-printed, multi-material, patient-specific simulator of the external and middle ear affected by stapes fixation. The simulator was designed for training in endoscopic stapes surgery (SS), addressing the lack of reliable training platforms for this technically challenging procedure. Imaging data from a CT scan of a patient were used to create a virtual 3D model of significant ear structures. The simulator consisted of a multi-use temporal bone holder and a single-use middle ear box, printed with material Jetting 3D printing technology. Eight participants to a university ear surgery course used the simulator to perform endoscopic stapes surgery. The surgical performance was evaluated using modified Objective Structured Assessment of Technical Skills (OSATS) scoring, and participant feedback was gathered through qualitative questionnaires. Seven of the eight participants successfully completed the simulated SS, with a mean surgical time of 24 min. OSATS scores showed acceptable performance, with 75% of participants achieving a score above 20. The tactile feedback, particularly for the stapes fixation, was well received, although the chorda tympani was deemed too fragile. The simulator was highly valued for visuomotor coordination development. The 3D Stapes Trainer represents a promising platform for training in endoscopic SS. Despite its limitations, the model provided young surgeons with a valuable platform to gain confidence in the steps of endoscopic SS, offering a high-fidelity simulation that contributes to the development of the technical skills required in this demanding procedure. N/A.

Abstract The congenital anomalies of the ossicular chain of the middle ear can exhibit various manifestations. Congenital middle ear anomalies are a rare cause of conductive hearing loss, with stapes fixation being the most common ossicular malformation. Among them, the congenital absence of the stapes is a rare condition. A 21-year-old male presented with decreased hearing in his right ear since childhood. Based on the clinical and audiological report, stapes fixation was suspected. An exploratory tympanotomy was performed, and there was congenital absence of stapes with malformed incus. The incus remnant was refashioned and placed over the oval window region. Postoperative audiogram did not show improvement in hearing. Reconstruction in cases of congenital absence of stapes is a challenge. The clinician should consider the various differential diagnosis of ossicular malformations when stapes fixation is suspected as the clinical diagnosis. This will help in better counseling of different options for surgical management and postoperative hearing outcomes.

To describe the surgical steps in endoscopic malleostapedotomy as a primary intervention and to evaluate the audiologic and surgical outcomes. Clinical capsule report. University hospital. Fourteen patients (10 males and 4 females) who underwent endoscopic malleostapedotomy as a primary intervention between April 2017 and July 2023 were enrolled in this study. Demographic data, surgical information, preoperative and postoperative pure-tone averages and air bone gaps, intraoperative and postoperative complications, and follow-up data were summarized and gathered in a database for further consideration and analysis. During endoscopic ear surgery, congenital ossicular chain malformation was present in 13 cases and tympanosclerosis in 1 case. The postoperative air-bone gap improved significantly compared with the preoperative gap (18.4 versus 47.4 dB HL, respectively), and the mean air-bone gap closure was 29 dB HL. In 14% of cases, the observed postoperative air-bone gap was less than 10 dB HL, and in 64%, it was between 11 and 20 dB HL. An ABG closure lower than 20 dB HL was achieved in a total of 78% of patients. There was no sensorineural hearing loss or persistent vertigo in the study sample. Two cases of prosthesis too short or prosthesis extrusion occurred after a mean follow-up of 16.9 months. Endoscopic malleostapedotomy as a primary intervention is a safe and reliable procedure and is a technique of choice in selected cases of stapes fixation with incus anomaly.

Genotypes and clinical phenotypes of pediatric patients with NOG variants: Middle ear surgical outcomes from a Tertiary Center in South Korea.

Endoscopic Management of Stapes Fixation Due to Stapedial Tendon Calcification

Distinct audiometric patterns in congenital round window atresia: A comparative study with common congenital middle ear anomalies

During an initial diagnostic assessment of an ear with normal otoscopic exam, it can be difficult to determine the specific pathology if there is a mechanical lesion. The audiogram can inform of a conductive hearing loss but not the underlying cause. For example, audiograms can be similar between the inner-ear condition superior canal dehiscence (SCD) and the middle-ear lesion stapes fixation (SF), despite differences in pathologies and sites of lesion. To gain mechanical information, wideband tympanometry (WBT) can be easily performed noninvasively. Absorbance , the most common WBT metric, is related to the absorbed sound energy and can provide information about specific mechanical pathologies. However, absorbance measurements are challenging to analyze and interpret. This study develops a prototype classification method to automate diagnostic estimates. Three predictive models are considered: one to identify ears with SCD versus SF, another to identify SCD versus normal, and finally, a three-way classification model to differentiate among SCD, SF, and normal ears. Absorbance was measured in ears with SCD and SF as well as normal ears at both tympanometric peak pressure (TPP) and 0 daPa. Characteristic impedance was estimated by two methods: the conventional method (based on a constant ear-canal area) and the surge method, which estimates ear-canal area acoustically.Classification models using multivariate logistic regression predicted the probability of each condition. To quantify expected performance, the condition with the highest probability was selected as the likely diagnosis. Model features included: absorbance-only, air-bone gap (ABG)-only, and absorbance+ABG. Absorbance was transformed into principal components of absorbance to reduce the dimensionality of the data and avoid collinearity. To minimize overfitting, regularization, controlled by a parameter lambda, was introduced into the regression. Average ABG across multiple frequencies was a single feature.Model performance was optimized by adjusting the number of principal components, the magnitude of lambda, and the frequencies included in the ABG average. Finally, model performances using absorbance at TPP versus 0 daPa, and using the surge method versus constant ear-canal area were compared. To estimate model performance on a population unknown by the model, the regression model was repeatedly trained on 70% of the data and validated on the remaining 30%. Cross-validation with randomized training/validation splits was repeated 1000 times. The model differentiating between SCD and SF based on absorbance-only feature resulted in sensitivities of 77% for SCD and 82% for SF. Combining absorbance+ABG improved sensitivities to 96% and 97%. Differentiating between SCD and normal using absorbance-only provided SCD sensitivity of 40%, which improved to 89% by absorbance+ABG. A three-way model using absorbance-only correctly classified 31% of SCD, 20% of SF and 81% of normal ears. Absorbance+ABG improved sensitivities to 82% for SCD, 97% for SF and 98% for normal. In general, classification performance was better using absorbance at TPP than at 0 daPa. The combination of wideband absorbance and ABG as features for a multivariate logistic regression model can provide good diagnostic estimates for mechanical ear pathologies at initial assessment. Such diagnostic automation can enable faster workup and increase efficiency of resources.

Benefit of the ADHEAR bone conduction device in patients with Otosclerosis with Stapes Fixation

Long-term outcomes following pediatric endoscopic titanium ossiculoplasty: A single-institution experience

Optical coherence tomography (OCT) vibrometry is a non-invasive tool for functional imaging of the middle ear. It provides spatially resolved vibrational responses and also anatomical images of the same ear. Our objective here was to explore the potential of OCT vibration measurements at the incus, as well as at the umbo, to distinguish among middle-ear disorders. Our approach was to build finite-element models of normal and pathological ears, generate large amounts of synthetic data, and then classify the simulated data into normal and pathological groups using a decision tree based on features extracted from simulated vibration magnitudes. We could distinguish between normal ears and ears with incudomallear joint (IMJ) disarticulation or stapes fixation, with the sensitivity and specificity both being 1.0; distinguish between stapes fixation and IMJ disarticulation with a sensitivity of 0.900 and a specificity of 0.889; and distinguish ears with ISJ disarticulation from normal ears with a sensitivity of 0.784 and a specificity of 0.872. Less extreme pathologies were also simulated. The results suggest that the vibration measurements within the middle ear that can be provided by OCT (e.g., at the incus) may be very valuable for diagnosis.

Imaging diagnosis of stapes fixation (SF) is challenging owing to a lack of definite evidence. We developed a comprehensive machine learning (ML) model to identify SF on ultra-high-resolution CT. We retrospectively enrolled 109 participants (143 ears) and divided them into the training set (115 ears) and test set (28 ears). Stapes mobility (SF or non-SF) was determined by surgical inspection. In the ML analysis, rectangular regions of interest were placed on consecutive axial slices in the training set. Radiomic features were extracted and fed into the training session. The test set was analyzed using 7 ML models (support vector machine, k nearest neighbor, decision tree, random forest, extra trees, eXtreme Gradient Boosting, and Light Gradient Boosting Machine) and by 2 dedicated neuroradiologists. Diagnostic performance (sensitivity, specificity and accuracy, with surgical findings as the reference) was compared between the radiologists and the optimal ML model by using the McNemar test. The mean age of the participants was 42.3 ± 17.5years. The Light Gradient Boosting Machine (LightGBM) model showed the highest sensitivity (0.83), specificity (0.81), accuracy (0.82) and area under the curve (0.88) for detecting SF among the 7 ML models. The neuroradiologists achieved good sensitivities (0.75 and 0.67), moderate-to-good specificities (0.63 and 0.56) and good accuracies (0.68 and 0.61). This model showed no statistical differences with the neuroradiologists (P values 0.289-1.000). Compared to the neuroradiologists, the LightGBM model achieved competitive diagnostic performance in identifying SF, and has the potential to be a supportive tool in clinical practice.

Background and Objectives Stapes surgery has been widely used to improve the conductive hearing loss caused by stapedial fixation. The purpose of this study is to evaluate the causes of stapedial fixation using audiological results of 100 stapes surgeries.Subjects and Method We reviewed the medical records of 100 consecutive stapes surgeries between June 2011 and December 2022. A total of 100 ears from 86 patients were included and the patient age ranged from 6 to 80 years. Hearing improvements of pure-tone thresholds were defined as successful when air-bone gap (ABG) was reduced to 20 dB or less, and as excellent when ABG was reduced to within 10 dB.Results The causative diseases of stapedial fixation were otosclerosis (n=74, 74%), ossicular anomaly (n=19, 19%) and chronic otitis media (n=7, 7%). Overall, the pre-operative bone-conduction thresholds/air-conduction thresholds (BC/AC) thresholds were 32±14/58±18 dB HL and ABG were 26±11 dB while the postoperative BC/AC thresholds were 29±15/36±18 dB HL and ABG were 7±8 dB. The postoperative ABG was excellent in 77% and successful in 93%. The postoperative ABG was excellent in 82.4% and successful in 97.3% of otosclerosis, excellent in 78.9% and successful in 89.5% of ossicular anomaly, and excellent in 14.3% and successful in 57.2% for chronic otitis media. ABG significantly improved less in revision cases than in primary otosclerosis cases (&lt;i&gt;p&lt;/i&gt;=0.006).Conclusion Stapes surgery is an effective method to improve hearing for various types of stapedial fixation. There was a difference in the degree of hearing improvement according to causative disorders.

Otosclerosis can lead to progressive conductive hearing loss, significantly affecting the quality of life. For patients who choose surgery, the tympanic membrane is elevated and middle ear space is explored. If the surgeon confirms that the stapes is fixed in the oval window, either a stapedotomy or stapedectomy can be performed. In the stapedotomy, the surgeon removes the stapes superstructure, creates a fenestration in the footplate, and places a prosthesis from the incus through the fenestration into the vestibule. In this instance, the patient was able to regain nearly all of the hearing that had been lost as a result of stapes fixation.

Congenital anomaly of ossicles in the middle ear is rare. We present a patient with Turner syndrome who presented with hearing loss. Pure-tone audiometry revealed bilateral moderate-to-severe hearing loss with conductive type at the lower and mixed type at the higher frequencies. There was a bone threshold dip at 2 kHz on both sides. The patient was diagnosed as having bilateral otosclerosis and underwent left middle ear surgery. Intraoperative findings showed an ossified stapedius tendon and a fixed monopod stapes with obliterated obturator foramen. The stapedius tendon was divided causing the footplate of the stapes to be mobile. This resulted in improved hearing with the closure of air-bone gap by around 40–50 dB. Stapes anomaly and ossified stapedius tendon causing stapes fixation may results in hearing loss with Carhart’s notch on pure-tone audiometry and misdiagnosed as otosclerosis. Surgery in which the ossified stapedius tendon is divided may help improve the patient’s hearing.

Introduction: The Carhart notch is a well-known sign of stapes fixation. However, previous studies have reported that the Carhart notch is not specific to stapes fixation and is also present in other middle ear diseases. Therefore, this study investigated the diagnostic value of threshold gap between air conduction and bone conduction (ABG) for stapes fixation, instead of the bone conduction dip representing the Carhart notch. Methods: A total of 199 ears that underwent exploratory tympanotomy were enrolled in this retrospective study. They were categorized into three groups according to surgical findings: stapes fixation (SF), other ossicle fixation (OF), and chain disconnection (CD). Preoperative pure-tone audiograms and impedance audiograms were compared between the groups. Results: The incidence of the Carhart notch did not differ between the groups. The ABG at 2,000 Hz showed a good diagnostic performance for distinguishing between the SF and CD groups (area under the curve, AUC = 0.816, p < 0.001), but poor performance for distinguishing between the SF and OF groups (AUC = 0.662, p = 0.003). Bone conduction at 2,000 Hz showed a moderate performance for distinguishing between the SF and CD groups (AUC = 0.707, p < 0.001) and did not show statistically significant results for distinguishing between the SF and OF groups (AUC = 0.594, p = 0.080). The tympanic membrane compliance was significantly higher in the CD group than in the SF group (p = 0.001). Conclusions: The Carhart notch was not a specific finding of SF. The sensitivity and specificity of ABG ≤15 dB at 2,000 Hz for distinguishing between SF and CD were 60.4% and 89.2%, respectively. To prepare for surgical interventions in patients with conductive hearing loss but a normal tympanic membrane, clinicians should comprehensively consider these results.

BackgroundA Carhart notch in the pure tone audiogram can be an indicator of stapes fixation in otosclerosis. This retrospective study of 157 patients with otosclerosis aimed to evaluate the association between the presence of a Carhart notch on the preoperative bone-conduction audiogram and postoperative hearing and balance evaluated by the Vestibular Disorders Activities of Daily Living scale.Material/MethodsPatients with suspected otosclerosis based on medical history and audiometric tests were considered. The analysis included 157 consecutive patients who underwent surgery in the years 2016 to 2019, in whom the diagnosis of otosclerosis was confirmed during surgery. Carhart notch was defined as an impairment in the bone conduction threshold of ≥7.5 dB for 2000 Hz frequencies above the mean thresholds at higher and lower adjacent frequencies. The Vestibular Disorders Activities of Daily Living subjective scale was used in the preoperative period and 4 and 12 months after surgery.ResultsThe preoperative presence of Carhart notch and progressive sensorineural hearing loss were statistically significantly correlated with more common onset of tinnitus and then dizziness (P=0.006). Preoperative vertigo was observed in patients who had Carhart notch observed in the preoperative audiometric test. This vertigo more commonly coexisted with profound sensorineural hearing loss and minor or no improvement in average values of bone conduction after surgery (P=0.002).ConclusionsPreoperative Carhart notch on audiogram and the severity of sensorineural hearing loss were associated with tinnitus and vertigo. However, preoperative Carhart notch was not associated with persistent postoperative tinnitus in patients with cochlear otosclerosis.