Traumatic dislocation of middle ear ossicles: A new computed tomography classification predicting hearing outcome.

OBJECTIVES: To assess the feasibility of radiologic measurements and find out whether hearing outcome could be predicted based on computer tomography (CT) scan evaluation in patients with temporal bone fractures and suspected ossicular joint dislocation. METHODS: We assessed 4002 temporal bone CT scans and identified 34 patients with reported ossicular joint dislocation due to trauma. We excluded those with no proven traumatic ossicular dislocation in CT scan and patients with bilateral temporal bone fractures. We measured four parameters such as malleus-incus axis distance, malleus-incus angle at midpoints, malleus- incus axis angle and ossicular joint space. The contralateral healthy side served as its own control. Hearing outcome 1-3 months after the index visit was analyzed. We assessed diagnostic accuracy and performed a logistic regression using radiologic measurement parameters for outcome prediction of conductive hearing loss (defined as >20dB air-bone gap). RESULTS: We found excellent inter-rater agreement on the measurement of axis deviation between incus and malleus in CT scans (interclass correlation coefficient 0.81). The larger the deviation of incus and malleus axis, the higher probability of poor hearing outcome (odds ratio (OR) 2.67 per 0.1mm, p = .006). A cut-off value for the axis deviation of 0.25mm showed a sensitivity of 0.778 and a specificity of 0.94 (p < .001) for discrimination between poor and good hearing outcome in terms of conductive hearing loss. CONCLUSION: Adequate assessment of high resolution CT scans of temporal bone in which ossicular chain dislocation had occurred after trauma was feasible. Axis deviations of the incus and the malleus were strongly predictive for poor hearing outcome in terms of air conduction 1-3 months after trauma. We propose a 3-level classification system for hearing outcome prediction based on radiologic measures.

Comparative study of unilateral conductive hearing loss in patients with an intact tympanic membrane.

BACKGROUND: The ossicular chain status is directly associated with the severity of conductive hearing loss (CHL) when the tympanic membrane (TM) is intact. AIMS/OBJECTIVES: To analyze the relationship between intraoperative findings and audiological data in patients with unilateral CHL and an intact TM. MATERIAL AND METHODS: Forty-three patients who underwent surgery at Xinhua hospital from January 1, 2012, to December 31, 2019, were included and categorized based on their intraoperative findings. Demographic data, intraoperative findings, and preoperative and postoperative audiological results of these patients were analyzed. RESULTS: Patients with ossicular chain disruption had significantly better outcomes than those with ossicular chain fixation (air conduction threshold [ACT]: 26.51 ± 8.82 vs. 44.08 ± 14.41 dB, p < .01; air-bone gap [ABG]: 10.66 ± 6.47 vs. 18.91 ± 9.32 dB, p = .04). Patients with ossicular chain deformities had a higher ACT (56.95 ± 13.81 vs. 44.56 ± 15.44 dB, p = .048) and a larger ABG (43.17 ± 9.94 vs. 33.02 ± 13.41 dB, p = .047) preoperatively than those with cholesteatoma; however, the postoperative outcomes between both patient groups were similar. CONCLUSIONS: Congenital ossicular chain anomalies had similar surgical outcome regardless of the pathology. In acquired cases, ossicular chain disruption had better audiological outcomes than ossicular chain fixation. SIGNIFICANCE: Ossicular chain reconstruction can significantly improve the hearing in patients with UCHL with intact TM.

Outcomes of ossicular disruption in traumatic facial paralysis: a case series.

BACKGROUND: As tympanotomy using the transcanal approach was a routine surgical technique for traumatic ossicular disruption, the efficacy of the posterior tympanum approach was rarely explored. AIM: This study aimed to investigate whether the hearing outcomes improved after simultaneous ossiculoplasty and facial nerve decompression using the posterior tympanum approach compared with the transcanal approach. MATERIAL AND METHODS: The data of 11 patients who underwent ossiculoplasty and facial nerve decompression using the posterior tympanum approach and 21 patients who underwent ossiculoplasty via transcannal approach were analyzed. RESULTS: The average air-bone gap (ABG) of patients undergoing posterior tympanotomy showed a statistically significant improvement. Postoperative ABG within 20 dB was observed in 81.8% of patients in the posterior tympanum group and 76.2% of patients in the transcanal group. However, the ABG closure in the two groups was not statistically different. CONCLUSIONS AND SIGNIFICANCE: Simultaneous ossiculoplasty using the posterior tympanum approach was practical, and the hearing outcomes were promising for the patients with traumatic facial nerve paralysis and ossicular disruption.

Transcanal endoscopic ear surgery for traumatic ossicular injury.

Background: Transcanal endoscopic ear surgery (TEES) for traumatic ossicular injuries (TOI) is not well studied.Objectives: To analyze the treatment outcomes of TEES for TOI.Material and methods: Retrospective case review of fifteen patients (15 ears) with TOI was performed. The patients underwent an either ossiculoplasty or stapes surgery according to status of the ossicular chain using ear endoscopes. Postoperative audiometric results and complications were analyzed.Results: All subjects demonstrated improvement in their air conduction threshold and air-bone gap (ABG). The mean preoperative air conduction threshold and ABG were 55.3 dB (SD: 12.8) and 33.0 dB (SD: 9.5), respectively. Postoperatively, the air conduction threshold and ABG significantly improved to 28.1 dB (SD: 16.0) and 8.1 dB (SD: 4.5), respectively. Separation of the incudomalleolar joint accompanied by defect of the tegmen, which was not discernible on preoperative imaging, could be identified without additional incision or mastoidectomy. No patients experienced complications or a sensorineural hearing loss. Conversion to open approach was not necessary for any of the 15 procedures performed.Conclusion and significance: TEES for TOI yielded favorable audiometric results without any complication. TEES can provide an alternative method to manage TOI with the advantage of avoidance of skin incisions and mastoidectomy.

Patología traumática de peñascos, un diagnóstico complejo. Claves para el informe / Traumatic injury of the petrous part of the temporal bone: keys for reporting a complex diagnosis

La fractura de peñascos constituye una lesión común de la base del cráneo, y la mayoría son el resultado de traumatismos de alta energía. Su reconocimiento en politraumatizados puede realizarse en las tomografías computarizadas de cráneo y cervicales. Los hallazgos directos e indirectos suelen ser suficientes para establecer el diagnóstico. Su identificación es importante debido a que el hueso temporal contiene estructuras críticas, y es posible errar debido a la complejidad de esta región, y su insuficiente vigilancia. Este trabajo revisa los puntos clave anatómicos, la sistematización de los hallazgos radiológicos y las clasificaciones usadas en fracturas de hueso temporal. Cobra relevancia la identificación y descripción de los hallazgos relativos a estructuras importantes de esta región, la búsqueda de fracturas no visibles sospechadas por signos indirectos, y la identificación de estructuras anatómicas que pueden simular fracturas. Pierden valor las clasificaciones clásicas, aunque siguen condicionando el manejo terapéutico

Fractures of the petrous part of the temporal bone are a common lesion of the base of the skull; most of these fractures result from high-energy trauma. In patients with multiple trauma, these injuries can be detected on CT scans of the head and neck, where the direct and indirect signs are usually sufficient to establish the diagnosis. It is important to these fractures because the temporal bone has critical structures and the complexity of this region increases the risk of error unless special care is taken. This article reviews the key anatomical points, the systematization of the imaging findings, and the classifications used for temporal bone fracture. We emphasize the usefulness of identifying and describing the findings in relation to important structures in this region, of looking for unseen fractures suspected through indirect signs, and of identifying anatomical structures that can simulate fractures. We point out that the classical classifications of these fractures are less useful, although they continue to be used for treatment decisions

Bone conduction hearing in the Guinea pig and the effect of artificially induced middle ear lesions.

Although human bone conduction (BC) hearing is well investigated, there is a lack of information about BC hearing in most other species. In humans, the amount of conductive loss is estimated as the difference between the air conduction (AC) and BC thresholds. Similar estimations for animals are difficult since in most species, the normal BC hearing thresholds have not been established. In the current study, the normal BC thresholds in the frequency range between 2 kHz and 20 kHz are investigated for the Guinea pig. Also, the effect of a middle ear lesion, here modelled by severing the ossicles (ossicular discontinuity) and gluing the ossicles to the bone (otosclerosis), is investigated for both AC and BC. The hearing thresholds in the Guinea pigs were estimated by a regression of the amplitude of the compound action potential (CAP) with stimulation level and was found robust and gave a high resolution of the threshold level. The reference for the BC thresholds was the cochlear promontory bone velocity. This reference enables comparison of BC hearing in animals, both intra and inter species, which is independent on the vibrator and stimulation position. The vibration was measured in three orthogonal directions where the dominating vibration directions was in line with the stimulation direction, here the ventral direction. The BC thresholds lay between -10 and 3 dB re 1 µm/s. The slopes of CAP growth function were similar for AC and BC at low and high frequencies, but slightly lower for BC than AC at frequencies between 8 and 16 kHz. This was attributed to differences in the stimulus levels used for the slope estimation and not a real difference in CAP slopes between the stimulation modalities. Two kinds of middle ear lesions, ossicular discontinuity and stapes glued to the surrounding bone, gave threshold shifts of between 23 and 53 dB for AC while it was below 16 dB when the stimulation was by BC. Statistically different threshold shifts between the two types of lesions were found where the AC threshold shifts for a glued stapes at 2 and 4 kHz were 9-18 dB greater than for a severed ossicular chain, and the BC threshold shifts for a glued stapes at 4 and 12 kHz were 8-9 dB greater than for a severed ossicular chain.

Traumatic Injury of the Petrous Part of the Temporal Bone: Keys for Reporting a Complex Diagnosis. / Patología traumática de peñascos, un diagnóstico complejo. Claves para el informe.

Fractures of the petrous part of the temporal bone are a common lesion of the base of the skull; most of these fractures result from high-energy trauma. In patients with multiple trauma, these injuries can be detected on CT scans of the head and neck, where the direct and indirect signs are usually sufficient to establish the diagnosis. It is important to these fractures because the temporal bone has critical structures and the complexity of this region increases the risk of error unless special care is taken. This article reviews the key anatomical points, the systematization of the imaging findings, and the classifications used for temporal bone fracture. We emphasize the usefulness of identifying and describing the findings in relation to important structures in this region, of looking for unseen fractures suspected through indirect signs, and of identifying anatomical structures that can simulate fractures. We point out that the classical classifications of these fractures are less useful, although they continue to be used for treatment decisions.

Conductive hearing loss with a "dry middle ear cleft"-A comprehensive pictorial review with CT.

Conductive hearing loss (CHL) commonly results from middle ear fluid and inflammation (otitis media). Less commonly in patients with CHL, the middle ear cleft is well aerated or 'dry' with absence of soft tissue or fluid clinically and on imaging. There are numerous causes for this but they can be clinically challenging to diagnose. This pictorial review aims to illustrate and discuss the CT features of both common and less common causes of CHL in patients with a "dry middle ear cavity".

Traumatic incudomalleolar disarticulation.

Traumatic head injuries can be associated with ossicular chain disruption. Especially in the setting of temporal bone fractures, proper alignment of the ossicular chain has to be insured. Loss of normal ossicular alignment is associated with conductive hearing loss. Treatment of ossicular chain disruption, so called ossiculoplasty, aims to restore proper anatomic alignment of the ossicles with osseous or cartilaginous autograft and/or prosthetic devices.

Drill-induced Cochlear Injury During Otologic Surgery: Intracochlear Pressure Evidence of Acoustic Trauma.

HYPOTHESIS: Drilling on the incus produces intracochlear pressure changes comparable to pressures created by high-intensity acoustic stimuli. BACKGROUND: New-onset sensorineural hearing loss (SNHL) following mastoid surgery can occur secondary to inadvertent drilling on the ossicular chain. To investigate this, we test the hypothesis that high sound pressure levels are generated when a high-speed drill contacts the incus. METHODS: Human cadaveric heads underwent mastoidectomy, and fiber-optic sensors were placed in scala tympani and vestibuli to measure intracochlear pressures (PIC). Stapes velocities (Vstap) were measured using single-axis laser Doppler vibrometry. PIC and Vstap were measured while drilling on the incus. Four-millimeter diamond and cutting burrs were used at drill speeds of 20k, 50k, and 80k Hz. RESULTS: No differences in peak equivalent ear canal noise exposures (134-165 dB SPL) were seen between drill speeds or burr types. Root-mean-square PIC amplitude calculated in third-octave bandwidths around 0.5, 1, 2, 4, and 8 kHz revealed equivalent ear canal (EAC) pressures up to 110 to 112 dB SPL. A statistically significant trend toward increasing noise exposure with decreasing drill speed was seen. No significant differences were noted between burr types. Calculations of equivalent EAC pressure from Vstap were significantly higher at 101 to 116 dB SPL. CONCLUSION: Our results suggest that incidental drilling on the ossicular chain can generate PIC comparable to high-intensity acoustic stimulation. Drill speed, but not burr type, significantly affected the magnitude of PIC. Inadvertent drilling on the ossicular chain produces intense cochlear stimulation that could cause SNHL.

The relationship between post-traumatic ossicular injuries and conductive hearing loss: A 3D-CT study.

PURPOSE: After a trauma, the conductive ossicular chain may be disrupted by ossicular luxation or fracture. Recent developments in 3D-CT allow a better understanding of ossicular injuries. In this retrospective study, we compared patients with post-traumatic conductive hearing loss (CHL) with those referred without CHL to evaluate the relationship between ossicular injuries and CHL. We also assessed the added value of 3D reconstructions on 2D-CT scan to detect ossicular lesions in patients surgically managed. METHODS: The CT scans were performed using a 40-section spiral CT scanner in 49 patients with post-traumatic CHL (n=29) and without CHL (n=20). Three radiologists performed independent blind evaluations of 2D-CT and 3D reconstructions to detect ossicular chain injury. We used the t-test to explore differences regarding the number of subjects with ossicular injury in the two groups. We also estimated the diagnostic accuracy and the inter-rater agreement of the 3D-CT reconstructions associated to 2D-CT scan. RESULTS: We identified ossicular abnormality in 14 patients out of 29 and in one patient out of 20 in the CHL and non-CHL groups respectively. There was a significant difference regarding the number of subjects with ossicular lesions between the two groups (P≤0.01). The diagnostic sensitivity of 3D-CT reconstructions associated with 2D-CT ranged from 66% to 100% and the inter-reader agreement ranged from 0.85 to 1, depending of the type of lesion. CONCLUSION: The relationship between ossicular lesion and the presence of CHL tightly correlated. 3D-CT reconstructions of the temporal bone are useful to assess patients in a post-traumatic context.

Surgical Management and Hearing Outcome of Traumatic Ossicular Injuries.

OBJECTIVE: The purpose of this study was to investigate etiological, clinical, and pathological characteristics of traumatic injuries of the middle ear ossicular chain and to evaluate hearing outcome after surgery. MATERIAL AND METHODS: Thirty consecutive patients (31 ears) with traumatic ossicular injuries operated on between 2004 and 2015 in two tertiary referral otologic centers were retrospectively analyzed. Traumatic events, clinical features, ossicular lesions, treatment procedures, and audiometric results were evaluated. Air conduction (AC), bone conduction (BC), and air-bone gap (ABG) were analyzed preoperatively and postoperatively. Amsterdam Hearing Evaluation Plots (AHEPs) were used to visualize the individual hearing results. RESULTS: The mean age at the moment of trauma was 27.9±17.1 years (range, 2-75 years) and the mean age at surgery was 33.2±16.3 years (range, 5-75 years). In 10 cases (32.3%), the injury occurred by a fall on the head and in 9 (29.0%) by a traffic accident. Isolated luxation of the incus was observed in 8 cases (25.8%). Dislocation of the stapes footplate was seen in 4 cases (12.9%). The postoperative ABG closure to within 10 and 20 dB was 30% and 76.7%, respectively. CONCLUSION: Ossicular chain injury by direct or indirect trauma can provoke hearing loss, tinnitus, and vertigo. As injuries are heterogeneous, they require a tailored surgical approach. In this study, the overall hearing outcome after surgical repair was favorable.

Conductive hearing loss with an intact tympanic membrane due to non-inflammatory causes.

OBJECTIVE: We analyzed audiologic and surgical findings in patients with conductive hearing loss (CHL) with an intact tympanic membrane (TM) that was of a non-inflammatory origin. METHODS: We reviewed data from patients who underwent exploratory tympanotomy for CHL with intact TM from January 1995 to November 2012. Patients with diseases of non-inflammatory origin were enrolled (69 patients; 79 ears). Patients were categorized into two groups: non-trauma (50 ears) and trauma (29 ears). Demographic data, intraoperative findings, and audiologic results were obtained and analyzed. RESULTS: Overall, the second decade was the most common age of diagnosis in both the non-trauma and trauma groups. Operative findings showed that ossicular dislocation was more prevalent than ossicular fixation; all trauma group subjects had ossicular dislocation. Short columellization or partial ossicular replacement was the most frequently adopted surgical procedures in both groups. Overall, audiologically, air-conduction thresholds (ACs) and air-bone gaps were significantly improved over the short- and long-term period in both groups. However, the non-trauma group had significantly higher preoperative ACs than the trauma group, especially at low frequencies. CONCLUSION: This study provides clinicians with useful information regarding the clinical characteristics of CHL with intact TM of non-inflammatory origin.

Influence of Ossicular Chain Damage on Hearing After Chronic Otitis Media and Cholesteatoma Surgery: A Systematic Review and Meta-analysis.

IMPORTANCE: Physicians should ideally be able to provide patients with chronic otitis media and/or cholesteatoma specific information about postoperative hearing outcome, based on their level of preoperative ossicular chain damage (OCD). OBJECTIVE: To identify the influence of preoperative OCD on hearing outcomes in patients after chronic otitis media and/or cholesteatoma surgery. DATA SOURCES: PubMed, EMBASE, and the Cochrane Library databases were systematically searched for available evidence, without any constraints, on December 13, 2014, for articles published between January 1, 1975, and December 13, 2014. STUDY SELECTION: We reviewed the literature for articles assessing the prognostic value of OCD on postoperative hearing outcome (air-bone gap [ABG] in decibels), using Austin-Kartush criteria or independent OCD classification systems. We assessed relevance and validity using a self-designed critical appraisal tool based on the Cochrane Collaboration's risk of bias tool. DATA EXTRACTION: Characteristics of study populations and postoperative ABGs in decibels were extracted from all included studies by 4 authors (E.F.B., M.N.G., N.J.K., A.S.H.J.L.). RESULTS: The tested hypothesis was formulated before data collection. Primary study outcome was defined as postoperative adult hearing outcomes after COM and/or cholesteatoma surgery defined as mean postoperative ABG. Our search yielded 5661 articles. Nine articles with high relevance were included. Pooled results of studies using the Austin-Kartush criteria showed a significant (P < .001) difference in mean ABG in favor of group B, when comparing group B (patients with malleus present, stapes absent; 11.1 [95% CI, 10.3-11.8] dB) to group C (patients with malleus absent, stapes present; 15.7 [95% CI, 14.6-16.7] dB) and group B to group D (patients with malleus absent, stapes absent; 16.5 [95% CI, 15.2-17.9] dB). Three studies using independent OCD classification criteria found no influence of stapes structure (intact stapes suprastructure, 13.5 [95% CI, 10.3-16.7], 15.1 [95% CI, 11.8-18.3], and 21.9 [95% CI, 15.0-28.8] dB vs absent stapes structure, 12.8 [95% CI, 9.5-16.1], 19.5 [95% CI, 14.9-24.1], and 30.2 [95% CI, 24.7-35.8] dB) on postoperative ABG. One study reported a significant (P = .04) difference in mean ABG between patients with present (18.9 [95% CI, 15.7-22.1] dB) and absent (24.4 [95% CI, 20.2-28.6] dB) malleus. CONCLUSIONS AND RELEVANCE: Pooled results of Austin-Kartush studies showed that in patients with COM, with or without cholesteatoma, the malleus status is a significant predictor of postoperative hearing outcome, independent of the stapes condition. Studies reporting on individual ossicle status supported this finding by showing that only malleus condition influenced postoperative hearing outcome. These findings are based on level IV evidence, which indicates the need for future high-level evidence studies.

Stapediovestibular dislocation depicted on temporal bone computed tomography with 3D rendering.

Stapediovestibular dislocation is an unusual form of ossicular trauma. In this article, a case of medial stapediovestibular dislocation and pneumolabyrinth due to penetrating injury with a stick diagnosed on temporal bone CT is described. In particular, 3D CT renderings can aid in the evaluation of the displaced ossicles.