Incudostapedial Joint Research Articles

Evaluation of the Curative Effects of Surgical Intervention in Cases of Congenital Malformation of the Ossicular Chain in Children.

Purpose: Congenital malformation of the ossicular chain results in challenges with hearing and language development in children. We aimed to analyze the clinical characteristics, prognosis, and surgical treatments of different types of congenital ossicular chain malformations in children. Methods: Eight cases (10 ears) treated between October 2019 and February 2022 were analyzed retrospectively. Patients were divided according to the location of the ossicular chain malformation and whether it was complicated by external ear malformation. Imaging, audiological examination, intraoperative exploration of the middle ear, and postoperative outcomes were recorded. Results: Group 1 incudostapedial joint deformity): 6 ears/60%; Group 2 (simple incus deformity): 2 ears/20%; Group 3 (simple malleus deformity): 2 ears/20%; Group A (with external ear malformations): 4 ears/40%; Group B (without external ear malformations): 6 ears/60%. The average hearing threshold before and after the operation was 51.25 ± 12.88 and 31.94 ± 12.96 dB, respectively. There were differences in the intervention effects of different malformed sites (Group 1: t = 5.139, P = .004; Group 2: t = 13.500, P = .047; Group 3: t = 15.000, P = .042). The effect of the intervention in cases of malformation with mobile stapes footplates was better than that with immobile stapes footplates (t = 4.082, P = .027). The effect of the intervention without external ear malformations was better than that with external ear malformations (t = 7.706, P = .001). Conclusions: The intervention yielded superior results in cases of malformation with mobile stapes footplates compared to those with immobile stapes footplates. Different intervention strategies should be determined through precise deformity assessments, with the degree of stapes mobility serving as a crucial factor in improving the prognosis.

Simulated Injuries of the Sheep Ossicular Chain: Correlations With Their Radiological Images.

Hypothesis We hypothesized that a sheep temporal bone would be a suitable model to study correlations between simulated middle ear injuries and their radiological appearances. Simulated ossicular chain injuries correlate well with their radiological images, and post-processing techniques provide optimal visualization of the sheep ossicles. Background The subtle ossicular trauma may be difficult to assess due to the small size of the structures. The precise radiological and clinical correlations of the ossicular injuries are not well documented. Methods The most common traumatic ossicular chain injuries were systematically simulated in the sheep temporal bone model. The images of the temporal bones were obtained with a high-resolution computed tomography scanner. The values of the dislocations were measured from the obtained images as well as in the temporal bones using calipers. Two observers independently evaluated the fine structures of the auditory ossicles using oblique multiplanar reconstructions (MPRs) and maximum intensity projections (MIPs). All segments of the facial nerve were also visualized. Results Optimal visualization planes of the sheep's middle ear joints have been obtained. The coincidence of simulated ossicular injuries in the specimens and MIPs was 40%. All structures of the ossicular chain were clearly distinguished except for the stapes footplate. Evaluation of the traumatic changes of the incudostapedial joint was challenging. Conclusions The sheep temporal bone is a suitable model for studying the correlations between pathological alterations in the ossicular chain and their radiological appearances. The post-processing MIP technique provides a more accurate and easier diagnosis of traumatic ossicular chain injuries than MPRs alone.

Comparison of Image Quality and Radiation Dose in Pediatric Temporal Bone CT Using Photon-Counting Detector CT and Energy-Integrating Detector CT.

Currently, there is a lack of research directly comparing photon-counting detector CT (PCD-CT) and energy-integrating detector CT (EID-CT) in pediatric temporal bone CT imaging. The purpose of this study was to compare the image quality and radiation dose of temporal bone CT scans in pediatric patients acquired with PCD-CT and EID-CT. The retrospective study included a total of 110 pediatric temporal bone CT scans (PCD-CT, n = 52; EID-CT, n = 58). Two independent readers evaluated the spatial resolution of 4 anatomic structures (tympanic membrane, incudostapedial joint, stapedial crura, and cochlear modiolus) and overall image quality by using a 4-point scale. Interreader agreement was assessed. Dose-length product for each CT was compared, and subgroup analyses were performed based on age (younger than 3 years, 3-5 years, 6-11 years, and 12 years and above). PCD-CT demonstrated statistically significantly higher scores than EID-CT for all items (tympanic membrane, 2.9 versus 2.4; incudostapedial joint, 3.6 versus 2.6; stapedial crura, 3.2 versus 2.4; cochlear modiolus, 3.4 versus 2.8; overall image quality, 3.6 versus 2.8; P < .05). Interreader agreement ranged from good to excellent (interclass correlation coefficients, 0.6-0.81). PCD-CT exhibited a 43% dose reduction compared with EID-CT, with a particularly substantial reduction of over 70% in the subgroups of children younger than 6 years. PCD temporal bone CT achieves significantly superior imaging quality at a lower radiation dose compared with EID-CT.

Clinical features and temporal CT findings in patients with Branchio-Oto-Renal or Branchio-Oto Syndrome

Objective: To assess the clinical features and CT diagnostic characteristics of Branchio-Oto-Renal or Branchio-Oto Syndrome. Methods: The temporal CT findings and clinical features observations of 13 patients with Branchio-Oto-Renal Syndrome (BORS) or Branchio-Oto Syndrome(BOS) confirmed by genetic testing were retrospectively analyzed. There were 8 males and 5 females, aged from 1 to 39 years, with a median age of 9 years, in which 3 pairs (6 cases) were parent-child relationship. Results: All of 13 cases had hearing loss and preauricular fistula, 11 cases accompanied by 2nd branchial fistulas. There were 20 ears of mixed hearing loss, 3 ears of sensorineural hearing loss, and 2 ears of conductive hearing loss. The mutation point of gene testing was located in EYA1 in 12 cases and SIX1 in 1 case. Twenty ears showed gradually narrowing of the diameter of basal turn, with hypoplasia in the second turn and aplasia in apical turn. There were irregular wall of vestibule and horizontal semicircular canal in 10 ears,widened vestibular in 7 ears, and vestibular fusion with horizontal semicircular canal in 3 ears. Three ears had an enlarged vestibular aqueduct, 8 ears showed enlargement of internal auditory canal. Seventeen ears had adhesion of malleolus to tympanic cavity. Six ears could not measured the incudostapedial joint angle by reason of tympanic inflammatory cover, 3 ears could not show incudostapedial joint, and 8 ears showed the incudostapedial joint angle more than 122°. Six ears showed poor oval window, and 1 ear had poor round window. Eighteen ears showed distended eustachian tube, and accompanied by tympanic or mastoiditis in 11 ears. Anterolateral shift of tympanum was found in 22 ears, 17 ears had low middle cranial fossa, and 3 ears had stenotic external auditory canal. Conclusions: Cochlear dysplasia, ossicular chain malformation and distended eustachian tube comprise the characteristic CT signs of BOS/BORS, which possesses versatile and complex CT findings. Temporal CT can accurately assess the important structures such as cochlea, ossicles, vestibule, semicircular canal, vestibular aqueduct and internal auditory canal. Combing with the clinical characteristics of bilateral, mixed hearing loss, preauricular fistula and branchial fistula can provide valuable information for early diagnosis and treatment.

Using bone cement in re-bridging incudostapedial joint

Objective: to evaluate the hearing outcomes of using ionomeric bone cement in re-bridging incudostapedial joint discontinuity. Methods: This study included 50 patients who had ossiculoplasty using ionomeric bone cement for re-bridging of incudostapedial joint. There pre and post-operative audiologic outcomes were evaluated and reviewed by using pure tone audiometry averages and the air bone gap values with a follow up period of one year. Results: 42 patients (84%) had a post-operative air bone gap less than 20 dB following one year of surgery. The pre and post-operative mean of pure tune averages were 50.04±7.28 and 32.74±7.07 respectively (P value&lt;0.01). The pre and post-operative mean of air bone gap were 36.56±6.41 and 17.60±5.77 respectively which was statistically significant (P value&lt;0.01). Conclusion: using of ionomeric bone cement is a good grafting material in incudostapedial re-bridging ossiculoplasty being cost effective, easy applicable and biocompatible and give a satisfactory hearing outcome in selected patients.

Bone mineral density of the incus body and long process in patients with chronic otitis media and its relationship with functional outcome in type II tympanoplasty

Background Inflammatory conditions such as chronic otitis media (COM) can cause irreversible impairments in the microarchitecture and functions of the incus, which subsequently leads to conductive hearing loss. Objectives To investigate bone mineral density (BMD) of the incus body (IB) and long process (ILP) on preoperative temporal CT in COM patients with and without incudo-stapedial joint discontinuity (ISJD), and also to determine the association between BMD values and the postoperative air-bone gap (ABG) in the ISJD group. Material and methods The mean IB density (IBD)/occipital bone density (OBD) and ILP density (ILPD)/OBD values were compared between the patients with and without ISJD. The correlation between ABG gain and preoperative incus density values was assessed in the ISJD group. Results The mean IBD/OBD and ILPD/OBD values were significantly higher in patients with intact ISJ. There was a moderate positive correlation between postoperative ABG gain and ILPD/OBD values in the ISJD group. Conclusion and significance The decrease in BMD of the incus may involve ILP as well as IB in patients with ISJD caused by ILP lysis in COM. A higher preoperative ILPD/OBD was correlated with a higher postoperative ABG gain in COM patients with ISJD.

Ossicular joint histopathology in cases of age-related hearing loss.

Age-related hearing loss (presbycusis) is a prevalent condition traditionally attributed to inner ear dysfunction. Little is known about age-related changes in the ossicular joints or their contribution to presbycusis. Herein, we performed an otopathologic evaluation of the ossicular joints in cases of presbycusis without a clear sensorineural explanation. Histopathologic analysis of the incudomallear (IM) and incudostapedial (IS) joints was performed in specimens from the National Temporal Bone Registry with audiometrically confirmed presbycusis but without histologically observed sensorineural, strial, or mixed features; deemed cases of "indeterminate" presbycusis. Specimens identified as "indeterminate" presbycusis (IP, n = 18) were compared to specimens with histologically confirmed sensorineural presbycusis (n = 16) and strial presbycusis (n = 11). Presbycutic specimens were also compared to age-matched controls (n = 9) and young controls (n = 14). The synovial space at the center of the IM joint was wider in the IP group (194 ± 36.8 μm) compared to age-matched controls (138 ± 36.5 μm), young controls (149 ± 32.2 μm), and ears with sensorineural presbycusis (148 ± 52.7 μm) (p < .05). The synovial space within the IS joint was wider in the IP group (105 ± 33.0 μm) when compared to age-matched controls (57.9 ± 13.1 μm) and ears with sensorineural presbycusis (62.3 ± 31.2 μm) (p < .05). IP ears have wider IM and IS joints when compared to ears with sensorineural presbycusis and age-matched controls. Findings point to a potential middle ear source of high frequency conductive hearing loss in a subset of presbycutic ears. Retrospective study.

Hearing Loss in Systemic Onset Juvenile Idiopathic Arthritis (Sojia) -A Single Case Study

Juvenile Rheumatoid Arthritis is a common type of arthritis in children under the age of sixteen. Females are more affected than males with ratio of 2:1. Systemic onset Juvenile Idiopathic Arthritis (SoJIA) is an immune driven inflammatory condition that develops in children. Although SoJIA can occur any time during childhood it usually starts before age five. Inflammation of internal organs and MAS (macrophage activation syndrome) is closely associated with SoJIA. Children with SoJIA have high levels of two powerful inflammatory protein (cytokines) called Interleukin -1 and Interleukin-6. The management of SoJIA follows up with NSAIDs, Corticosteroids, DMARDs and inflammatory cytokine blockade. The incudomalleolar and incudostapedial joint are synovial in nature and hence could be involved in inflammatory process. Immune complex mediated vasculitis and ototoxic side effects may cause a pathological inner ear. Thus individuals with SoJIA are at higher risk of hearing impairment.

Diagnostic Value of Cone-Beam Computed Tomography in Conductive or Mixed Hearing Loss with Intact Tympanic Membrane.

Conductive or mixed hearing loss with an intact tympanic membrane is a group of diseases characterized by similar clinical symptoms. Definitive diagnosis depends on the findings of exploratory tympanic surgery. Cone-beam computed tomography (CBCT) has great potential for middle ear imaging. This study evaluated the diagnostic value of CBCT for conductive or mixed hearing loss with an intact tympanic membrane. CBCT and high-resolution computed tomography (HRCT) imaging data were collected from patients with an intact eardrum who received medical treatment in our hospital for conductive or mixed hearing loss from October 2020 to May 2023. The imaging characteristics and diagnostic values of CBCT and HRCT were analyzed. A total of 137 patients who met the inclusion criteria and underwent CBCT were enrolled, including 89 with otosclerosis, 41 with ossicular chain interruption, and 7 with tympanosclerosis. CBCT clearly displayed a middle ear focus, such as low-density lesions located in the fissula ante fenestram, ossicular chain malformation or dislocation, and tympanic calcification foci. The area under the curve values for otosclerosis, ossicular chain interruption, and tympanic sclerosis were 0.934, 0.967, and 0.850, respectively. CBCT was more effective than HRCT for visualizing the lenticular process, incudostapedial joint, and stapes footplate. CBCT of the middle ear demonstrated higher-quality imaging to improve the diagnosis of conductive or mixed hearing loss with an intact tympanic membrane. Therefore, CBCT is recommended for further investigation of noninflammatory diseases of the middle ear with no special findings on HRCT.

Minimally invasive ossiculoplasty via an endoscopic transtympanic approach

IntroductionThe aim of this study was to evaluate the feasibility of ossiculoplasty via a minimally invasive endoscopic transtympanic approach (ETTA). Case seriesWe investigated the exposure of target structures (incus and stapes) on 4 human temporal bones by placing an endoscope into the middle ear cleft through the 4 tympanic quadrants. Then, on 3 additional specimens, we performed an incudostapedial disjunction and repaired it with a drop of hydroxyapatite cement via ETTA. We measured the size of tympanic perforation, and the acoustic transfer function of the middle ear (125–8000Hz) before and after repair by placing an insert in the external auditory canal and recording the acoustic signal in the utricle by a microphone. The acoustic signal gain was estimated in dB μV. Exposure was similar in all four quadrants but ergonomics was better with a posteroinferior myringotomy. Ossicular chain repair was conducted successfully in all cases and the acoustic transfer function of the middle ear was significantly improved. Residual tympanic perforation (n=3) was 2±0.3mm in diameter. ConclusionETTA to reconstruct incudostapedial joint with bone cement was feasible and effective. It opens perspectives for robot-based procedures guided by augmented reality.

Variation of the stapes and its surrounding anatomical structures based on micro-computed tomography.

Stapedotomy is the most efficient treatment for otosclerosis. The anatomical structure of the operation area is complex, but it has a great impact on the postoperative effect. We measure the anatomical parameters of the stapes and its surrounding structures to provide an anatomical reference for stapes surgery in otosclerosis. Fifteen adult cadaver heads (30 samples) were scanned using micro-CT. The stapes, facial nerve and external auditory canal were reconstructed by image processing. The stapes parameters and relationships between the stapes and surrounding structures were measured using a three-dimensional reconstruction model. The length, width and thickness of the stapes footplate were 2.93 ± 0.17 mm, 1.46 ± 0.08 mm and 0.30 ± 0.11 mm, respectively. The distance between the stapes footplate and long process of the incus was 3.79±0.39 mm. The angle of the incudostapedial joint was 88.29 ± 11.58°. The distance from the center of the stapes footplate to the facial canal was 1.60 ± 0.34 mm. In simulated stapes surgery, the minimum depth of the external auditory canal to be removed was 2.17 ± 0.91 mm, and no significant difference was found between the left and right sides and between men and women (P > 0.05). A three-dimensional model of the stapes bone and its surrounding anatomical structures was established based on Micro-CT imaging. Anatomical parameters of the stapes bone and its surrounding structures were measured using the model. In stapedotomy, the implanted piston diameter should be around 0.6mm, with a length of approximately 4.6mm. Care should be taken to protect the facial nerve canal during the surgery. These data provide reference for otologists.

Assessment of the ability of the radiological incudo-stapedial angle to predict the stapedotomy technique type: a prospective case-series study.

This study aimed to propose a radiological classification of the incudo-stapedial angle by preoperative high-resolution computed tomography (HRCT) images and to highlight its importance for predicting the use of reversal-steps stapedotomy (RSS) rather than the traditional non-reversal technique. We included 83 candidates for stapedotomy operation. Two physicians measured the radiological incudo-stapedial joint angle in the preoperative HRCT. According to this measurement, the radiological incudo-stapedial joint was classified into three types: obtuse, right, and acute. In addition, this radiological classification was correlated with the intraoperative use of the stapedotomy technique, either reversal or non-reversal. The RSS technique was used in forty-two (97.7%) cases with an obtuse angle and twenty-six (89.7%) with a right angle. At the same time, the traditional non-reversal technique was used in all patients with an acute angle. The three groups differed significantly regarding the method used for stapedotomy (P value < 0.001). Moreover, Spearman's correlation coefficient revealed a significant correlation between the used technique and the radiological type of the incudo-stapedial angle (P value < 0.001). This prospective study proposed a preoperative radiological classification of the incudo-stapedial angle. This classification was significantly correlated with the type of stapedotomy technique. The RSS technique was feasible in most cases with an obtuse and right radiological incudo-stapedial angle. In contrast, the non-reversal method was used in all patients with an acute radiological incudo-stapedial angle. This radiological classification could predict the choice for the stapedotomy technique with an accuracy of 95.18%, a sensitivity of 73.33%, and a specificity of 100%.

Hearing Outcome After Incudo-stapedial Joint Reconstruction Using Conchal Cartilage Interposition Graft.

Ossicular chain defects secondary to Chronic otitis media most frequently involves the incudo-stapedial joint. This study observes the effect of incudo-stapedial joint reconstruction using conchal cartilage interposition graft on hearing of the patient. Fifty-three patients with chronic otitis media of inactive mucosal type with incudostapedial necrosis of less than half of long process of incus were posted for tympanoplasty with incudostapedial joint reconstruction using autologus conchal cartilage. Their hearing outcome was analysed by comparing the pre-operative and 12 weeks post-operative Pure Tone Audiogram. A statistically significant improvement is seen in air conduction by 14.66 dB after incudo-stapedial joint reconstruction using conchal cartilage (p value 0.0001), whereas improvement seen in bone conduction was statistically insignificant. 52 (98.1%) patients had ≤ 40 dB post-op AC and 1 (1.9%) had > 40 dB.. Conchal cartilage is an easy-to-harvest, biocompatible and cost effective graft material. It gives hearing results comparable to other materials.

Characterization of middle ear soft tissue damping and its role in sound transmission

Damping plays an important role in the middle ear (ME) sound transmission system. However, how to mechanically characterize the damping of ME soft tissues and the role of damping in ME sound transmission have not yet reached a consensus. In this paper, a finite element (FE) model of the partial external and ME of the human ear, considering both Rayleigh damping and viscoelastic damping for different soft tissues, is developed to quantitatively investigate the damping in soft tissues effects on the wide-frequency response of the ME sound transmission system. The model-derived results can capture the high-frequency (above 2kHz) fluctuations and obtain the 0.9kHz resonant frequency (RF) of the stapes velocity transfer function (SVTF) response. The results show that the damping of pars tensa (PT), stapedial annular ligament (SAL) and incudostapedial joints (ISJ) can help smooth the broadband response of the umbo and stapes footplate (SFP). It is found that, between 1 and 8kHz, the damping of the PT increases the magnitude and phase delay of the SVTF above 2kHz while the damping of the ISJ can avoid excessive phase delay of the SVTF, which is important in maintaining the synchronization in high-frequency vibration but has not been revealed before. Below 1kHz, the damping of the SAL plays a more important role, and it can decrease the magnitude but increases the phase delay of the SVTF. This study has implications for a better understanding of the mechanism of ME sound transmission.

Audiological outcome after stapes surgery in relation to prosthesis type

PurposeDifferent techniques are used to fix crimp and CliP® Piston stapes prostheses to the long process of the incus (LPI). The CliP® Piston provides a stiff connection in contrast to the static bended loop of the crimp prosthesis, which imitates the physiological incudostapedial joint (ISJ) and thereby potentially leads to different hearing outcome.MethodsIn a retrospective single-center study of German-speaking one hundred and ninety patients who underwent stapes surgery CliP® Piston or crimp prostheses between the years of 2016 and 2019 by the same surgeon and in the same setting. Pre- and postoperative bone- (BC) and air-conduction (AC) pure-tone thresholds, pre- and postoperative air–bone gap (ABG) for 0.5, 1, 1.5, 2, 3, 4 kHz and the surgery time were examined.ResultsThe postoperative bone conduction thresholds were significantly lower in the frequencies between 0.5 and 3 kHz and the mean ABG was < 10 dB in most cases independent of the prosthesis used. Crimp prosthesis showed a significantly better closure of the ABG at 0.5 kHz.ConclusionsThe audiological outcome after stapes surgery is dependent on the type of prosthesis used, as reflected by the frequency-specific air–bone gap. The better ABG closure with the crimp prosthesis might be the result of the connection to the LPI imitating the physiological ISJ. The crimp prosthesis may be the better choice if use of hearing aids is expected postoperatively.

Hearing outcomes after incudo-stapedial rebridging versus partial ossicular replacement prosthesis in chronic suppurative otitis media

Aim: To evaluate the early postoperative hearing results after Incudo-stapedial rebridging versus partial ossicular replacement prosthesis application in cases of incudo-stapedial discontinuity due to chronic suppurative otitis media.Study Design: A prospective randomized comparative clinical trial.Place and Duration of Study: Otolaryngology Department, Tanta University, Egypt from January 2018 to June 2021.Methodology: Inclusion criterion was cases with CSOM with ABG more than 30 dB and adequate cochlear reserve. Study population were sixty consecutive cases with incudo-stapedial erosion more than 2-millimeter gap. Thirty of them were candidates for incudo-stapedial rebridging using tragal cartilage strip graft and glass ionomer bone cement. The other thirty patients were candidates for PORP. Tympanoplasty was done for each case of the two groups.Main Outcome Measures: hearing assessment following surgical procedures.Results: Postoperative air conduction significantly decreased compared to baseline in each group. By comparing the results of both techniques, pre and postoperative air conduction were insignificantly different.ABG significantly decreased postoperatively compared to baseline in each group. By comparing between both techniques, pre and postoperative ABG were insignificantly different.Conclusions: Among chronic suppurative otitis media patients with ossicular erosion, our study showed that PORP and cartilage graft with glass ionomer bone cement effectively improved hearing levels when used for the reconstruction of the incudostapedial joint during tympanoplasty.

A Case of Idiopathic Malleus Handle Fracture

The most common injury of the ossicle chain is traumatic incudostapedial joint dislocation. Cases of fracture of the incus or stapes have also been reported, but malleus fracture without injury of the tympanic membrane or other ossicles is rare. Our patient was a 56-year-old man who presented to our outpatient department with an 8-day history of right hearing loss at the time of waking up. On examination, the anterior part of the right tympanic membrane looked dark purple. Pure-tone audiogram showed mid-to-high frequency conductive hearing loss on the right side. A temporal bone CT showed no obvious fracture of the ossicles, but an opacity was noted anterior to the malleus handle, suggesting middle ear hemorrhage. Eight months later, endoscopic ear surgery was performed. The fracture was located near the lateral process of the malleus, and a tragus cartilage graft was placed between the malleus and the tympanic membrane. Postoperatively, the right conductive hearing loss improved. Although isolated malleus handle fracture is rare, it is necessary to keep in mind the possibility of such ossicular bone injuries in daily practice.

Combined analysis of finite element model and audiometry provides insights into the pathogenesis of conductive hearing loss.

The middle ear transmits sound to the inner ear via vibrations in the eardrum and ossicles, and damage to the middle ear results in conductive hearing loss. Although conductive hearing loss can be corrected by surgery, the currently available clinical investigations cannot always diagnose the ossicular chain pathology underlying the conductive hearing loss, and even intraoperative findings can be equivocal. Acoustic analysis using finite element models (FEMs) can simulate the sound pressure change at an arbitrary site for each frequency. FEMs are used in acoustic engineering to simulate the frequency-dependent sound pressure distribution at discrete cells in a simulated model and analyze the effects of specific parameters on the audiogram. However, few reports have compared the numerical results obtained using FEMs with data from clinical cases. We used FEMs to simulate audiograms of the air-bone gap (ABG) for various ossicular chain defects and compared these with preoperative audiograms obtained from 44 patients with a normal tympanic membrane who had otosclerosis, middle ear malformations or traumatic ossicular disruption. The simulated audiograms for otosclerosis and attic fixation of the malleus-incus complex both exhibited an up-slope but could be distinguished from each other based on the ABG at 1000 Hz. The simulated audiogram for incudostapedial joint discontinuity exhibited a peak at around 750 Hz and a down-slope above 1000 Hz. In general, the simulated audiograms for otosclerosis, attic fixation and incudostapedial joint discontinuity were consistent with those obtained from clinical cases. Additional simulations indicated that changes in ossicular mass had relatively small effects on ABG. Furthermore, analyses of combination pathologies suggested that the effects of one defect on ABG were added to those of the other defect. These FEM-based findings provide insights into the pathogenesis of conductive hearing loss due to otosclerosis, middle ear malformations and traumatic injury.

Long-term outcomes of stapes surgery

ObjectiveHearing improvement following stapes surgery is generally good; however, we sometimes encounter patients where hearing loss gradually progresses over the long term. In this study, we investigated the causes of hearing loss in these cases. MethodsA total of 30 ears from 23 patients, who underwent stapes surgery at Kitasato University Hospital from 2001 to 2021 and were followed up for ≥5 years, were included in the study. Changes in air conduction (AC) and bone conduction (BC) thresholds were measured, and hearing evaluation was performed by calculating the air–bone gap (ABG) at the mean of 4 frequencies. Cases with a postoperative ABG of ≤10 dB at 6 months after surgery were classified into the following groups according to their hearing changes at 5 years after surgery: Group A (no ABG increase of ≥10 dB and no AC threshold increase of ≥10 dB) and Group B (an ABG increase of ≥10 dB and an AC threshold increase of ≥10 dB). In groups A and B, we examined factors affecting long-term postoperative results. In addition, the patients who underwent reoperation were examined. ResultsThe AC thresholds 6 months and 5 years after surgery decreased significantly compared with those before surgery (p < 0.01); however, the BC thresholds 6 months and 5 years after surgery did not vary significantly from those before surgery (p > 0.05). Group A included 16 ears from 13 patients (53.3%), and Group B included 3 ears from 3 patients (10.0%). There were no significant differences in age, sex, surgical method, piston type, piston length, presence of incudostapedial joint subluxation, computed tomography findings, and preoperative ABGs between groups A and B (p > 0.05). A total of 6 reoperations were performed in 3 ears from 3 patients, and there were 5 operations with the platinotomy hole to be closed by bone regrowth and 3 operations with the narrowed long process of the incus. ConclusionIn 10.0% of the patients who underwent stapes surgery, the ABG improved 6 months after surgery; however, the AC threshold and ABG increased 5 years after surgery. Our findings suggested that piston displacement and the platinotomy hole to be closed by bone regrowth are possible causes of hearing loss in cases where hearing loss progresses in the long term after stapes surgery.

Traumatic Stapes Luxation into the Vestibule.

We report a rare case of traumatic stapes luxation into the vestibule. A 31-year-old female visited an emergency room with sudden onset of vertigo and conductive hearing loss after accidental penetrating injury to the right ear. Temporal bone computed tomography detected pneumolabyrinth, with a shade of whole intact stapes in the vestibule. Under exploratory tympanotomy, we observed a separated incudostapedial joint, and the stapes was depressed into the vestibule. The stapes was pulled out to the middle ear, and stapedectomy was performed; the crus were cut, the suprastructure was removed, and the fractured footplate and the long process of the incus were connected with a piston wire. The stapes footplate was sealed with soft tissue and surgical glue. Vertigo rapidly subsided after surgery, and hearing was improved to normal range. However, hearing loss at high frequencies was not recovered, probably because of inner ear damage due to the stapes depressed into the vestibule or surgical manipulation within the vestibule. Traumatic ossicular dislocation is not an uncommon occurrence in otolaryngologic practice, but stapes luxation is rare. Here, we report a rare case with successful repair. This report could serve as a basis for proper treatment in similar cases in the future.