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The Laryngoscope
C 2015 The American Laryngological,
V
Rhinological and Otological Society, Inc.
Trauma Patterns, Symptoms, and Complications Associated With
External Auditory Canal Fractures
Daniela M. Burchhardt, MD; John David, MS; Robert Eckert, MA; Natasha L. Robinette, MD;
Michael A. Carron, MD; Giancarlo F. Zuliani, MD
Objectives/Hypothesis: External auditory canal (EAC) trauma, although rare, can have significant long-term adverse
outcomes. This study aims to investigate the frequency, treatment, and complications of external ear canal injury in association with mandibular and temporal bone trauma.
Study Design: Retrospective chart review.
Methods: Computed tomography images with mandibular or temporal bone trauma were reviewed for EAC fractures.
Patient data were collected from initial presentation and subsequent follow-up clinic visits.
Results: Thirty-nine percent of temporal bone fractures and 3.3% of mandible trauma involved the EAC. In particular,
10% of condylar or subcondylar trauma included an EAC fracture (P 5 0.0006). One patient sustained bilateral EAC fractures
despite an isolated, unilateral condylar fracture. The most common presenting sign was blood in the external auditory canal.
Two patients underwent exam under anesthesia and removal of debris and stenting as treatment, whereas 42% of the
patients were placed on otic drops and 5% received packing or a stent. Follow-up data were only available for 16% of the
patients. Hearing loss from otic capsule involvement or ossicular chain disruption were follow-up complaints, and one patient
had persistent canal stenosis.
Conclusions: External auditory canal trauma is present in a significant proportion of mandibular and temporal bone
trauma, including both condylar and noncondylar fractures with a higher incidence of condylar fractures. One case was seen
with bilateral EAC fractures despite a unilateral mandibular fracture. Complications of these fractures can include hearing
loss and canal stenosis; however, additional outpatient follow-up is needed to further elucidate long-term complications and
shape treatment recommendations.
Key Words: EAC trauma, external auditory canal fracture, mandibular trauma, condylar trauma, temporal bone trauma.
Level of Evidence: 4.
Laryngoscope, 125:1579–1582, 2015
INTRODUCTION
In trauma patients, blood in the external auditory
canal (EAC) is usually viewed as an indication to suspect basilar skull fracture. Since the late 1960s, the literature has shown that mandibular trauma needs to be
considered in these patients, and a link has been established between mandibular condyle trauma and EAC
lacerations and/or fractures.1 Despite this, there is a
paucity of reports on EAC trauma secondary to mandibular trauma, in particular regarding treatment, potential complications, and long-term sequelae. In fact, since
the advent of current day imaging techniques such as
From the Department of Otolaryngology–Head and Neck Surgery
(D.M.B., M.A.C., G.F.Z.), the Department of Oncology, Karmanos Cancer
Institute (N.L.R.); (J.D.), Wayne State University School of Medicine,
Detroit, Michigan, U.S.A.
Editor’s Note: This Manuscript was accepted for publication
February 10, 2015.
Presented at Triological Society Meeting at Combined Otolaryngology Spring Meeting, Las Vegas, Nevada, U.S.A., May 15–16, 2014.
The authors have no funding, financial relationships, or conflicts
of interest to disclose.
Send correspondence to Giancarlo Zuliani, MD, Department of
Otolaryngology–Head and Neck Surgery, Wayne State University School
of Medicine, 4201 St Antoine, 5E-UHC, Detroit, MI 48201.
E-mail: [email protected]
DOI: 10.1002/lary.25246
Laryngoscope 125: July 2015
computed tomography (CT) scanning, most of the literature on EAC fractures consists of isolated case reports.
We therefore conducted a retrospective review to further
elucidate this link between EAC fractures and mandibular trauma and/or temporal bone trauma—and evaluated
the clinical interventions with a review of sequelae.
MATERIALS AND METHODS
In an institutional review board-approved study, a retrospective chart review of patients with EAC fractures in association with mandibular and/or temporal bone trauma was
conducted. Charts from the year 2000 to 2013 were collected
based on International Classification of Diseases, Ninth Revision, codes for EAC fractures, EAC stenosis/wound/trauma,
temporal bone fractures, and temporomandibular joint syndrome and mandible trauma at hospitals affiliated with the
Otolaryngology–Head and Neck Surgery Department at Wayne
State University, Detroit, Michigan. Patients under the age of
16 were excluded. Close to 600 CT scans were reviewed to identify EAC fractures; and if present, further data were collected
that included demographics such as sex, age, gender, alcohol/
drug use, mechanism of injury, presenting signs and symptoms,
and interventions done. When available, follow-up data from
clinic visits were collected. Statistical analysis consisted of the
Welch’s variant of the Student t test, which was used to compare small samples that were not necessarily of equal size from
populations whose variances were not necessarily equal.
External Auditory Canal Fractures: Burchhardt et al.
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RESULTS
Out of 122 temporal bone fractures that were
reviewed (88% otic capsule-sparing and 12% otic capsule-involving), 39% involved the external auditory
canal. Of 481 mandibular fractures, 3.3% were associated with an EAC fracture, and 10% of condylar or subcondylar
fractures
included an
EAC fracture
(P 5 0.0006) (Fig. 1). No significant difference was found
between other fracture location combinations or laterality. One case was noted to have bilateral EAC fractures
despite only an isolated, unilateral condylar fracture.
Classification of temporal bone trauma into longitudinal,
mixed, or transverse, as well as otic capsule-sparing or
otic capsule-involving did not reveal any significant difference in association with EAC fractures. Computedtomography scan thickness was recorded and did not
vary significantly between trauma with or without EAC
fractures.
Patients sustaining EAC fractures included all
adult age ranges, with a predilection for men aged in
their 20s through 40s. Injury mechanisms were evenly
distributed among assaults, falls, and bicycle injuries for
mandible-associated trauma; whereas falls, assault, and
motor vehicle accidents shared an increased representation in temporal trauma-associated canal fractures,
although no significant predilection was found. The most
common presenting sign and symptom was blood in the
EAC (81% for mandible and 93% for temporal trauma
with EAC fracture). Others include hearing loss, hemotympanum, or a laceration, but no statistical significance
was seen (Fig. 2). Two patients with condylar and EAC
fractures underwent exam under anesthesia and
removal of debris, as well as stenting, as treatment; 42%
of the patients were placed on otic drops; and 5%
received packing or a stent. Follow-up data were only
available for 16% of the patients. Hearing loss from otic
capsule-involving or ossicular chain disruption were the
main follow-up complaints; however, one patient developed persistent canal stenosis and conductive hearing
loss, which eventually resolved by 6 months postinjury.
DISCUSSION
External auditory canal trauma is present in a significant proportion of mandibular and temporal bone
Fig. 1. Incidence of external auditory canal fractures in mandible
and temporal bone trauma. [Color figure can be viewed in the
online issue, which is available at www.laryngoscope.com.]
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1580
Fig. 2. N numbers listed reflect the number of patients whose
records specifically documented the presence or absence of the
particular sign or symptom of EAC fractures associated with mandibular and temporal trauma. EAC 5 external auditory canal;
TM 5 temporomandibular joint; TMJ 5 temporomandibular joint
syndrome. [Color figure can be viewed in the online issue, which
is available at www.laryngoscope.com.]
trauma. In 1977, Schmidseder et al. found a 15% incidence of EAC fractures with condylar fractures.1 Since
then, most reports consist of case reports. Only soft tissue in the form of an adipose pad and the thin tympanic
plate separate the EAC from the condyle. The thin skin
overlying the tympanic plate constitutes the lining of
the anterior wall of the EAC. In contrast, the posterior
medial aspect of the glenoid fossa consists of soft tissue
only and lacks bony support.2 This delicate anatomy can
help explain the link between condylar trauma and
injury of the EAC, and several mechanisms have been
proposed: A posterior displacement of the condyle can
split the cartilaginous part of the EAC or occasionally
fracture the tympanic plate if the condyle is forced
against it.2–4 It has been suggested that posterior dislocation may be associated with an edentulous state.2
Another theory suggests that anterior medial displacement of the condylar head (which is the most common
type of dislocation) could cause a tear at the junction of
the bony and cartilaginous components.5 In instances
when no fracture or displacement was found, it was
hypothesized that a transient posterior displacement of
the condylar head was responsible for an isolated
anterior-wall EAC laceration.4
In our study, EAC fractures were significantly more
common in temporal bone trauma, at times because of
direct involvement in the fracture line (Fig. 3). An overall
3% incidence was seen in mandibular fractures and 10%
in condylar or subcondylar fractures (Fig. 4), with a P
value of 0.0006 comparing condylar- to noncondylarassociated EAC fractures. The 1% incidence of specifically
noncondylar-associated EAC fractures among mandible
trauma is consistent with the hypothesis by Martis et al.
that a temporary displacement of the condyle can lead to
EAC trauma.4 This proposed mechanism could also
explain how one patient sustained bilateral EAC fractures
despite only an isolated unilateral condylar fracture.
External Auditory Canal Fractures: Burchhardt et al.
Fig. 3. Temporal bone fracture extending into the external auditory
canal.
All of the patients in this study received CT scans.
Reports suggest that because tympanic plate fractures
may present with minimal EAC bleeding they require a
thorough examination of the external ear and the canal
to evaluate for edema, lacerations, or bulges. Any positive findings indicate that a CT scan is required for a
diagnosis.6 In fact, Avrahami et al. recommend CT as
the first-line modality to evaluate fractures in patients
presenting with trismus and unilateral ear bleeding in
order to avoid repeat exposure to radiation for further
imaging.7
Interestingly, an isolated case was seen for which
no evidence of CT findings of an ipsilateral fracture
were seen, yet exam under anesthesia revealed bony
fragments in the canal. This finding highlights the
importance of a thorough physical exam and review of
imaging (Fig. 5).
Current treatment suggestions are not fully
addressed in the literature; packing the canal with antibacterial ointment to prevent future stenosis, in addition
to treatment of the mandible fracture, are the most common interventions. Reports of long-term sequelae are
sparse, and isolated reports exist of partial canal steno-
sis. This occurred in a case of an EAC laceration without
fracture of temporal plate, which was the result of a
nonfractured, posteriorly displaced condyle,2 suggesting
the importance of further exploring treatment options
and their efficacy. Hearing loss is frequently cited as a
presenting symptom that often resolves; yet it can persist, particularly in temporal plate fractures.8 Furthermore, one case of a cholesteatoma is presented in the
literature.9
In our study, blood in the EAC was the single most
common presenting sign and symptom, although records
of ear exams were not always available. Most fractures
were treated with otic drops and some stented with
XeroformTM gauze, Covidien, Mansfield, MA. Several
isolated cases were evaluated via exams under anesthesia at the time of fracture repair, followed by suctioning
of debris and stenting with XeroformTM gauze, Covidien,
Mansfield, MA. However, due to the limited follow-up
rates in our patient population, the sample size is too
small for significant conclusions regarding the efficacy of
intervention and long-term complications.
External auditory canal trauma is present in a significant proportion of mandibular and temporal bone
trauma, with a significantly increased incidence in condylar compared to noncondylar trauma. Rarely, EAC fractures can be present without ipsilateral mandibular
trauma, highlighting the importance of thorough physical
examination and radiology review. Additional outpatient
follow-up is necessary to further elucidate long-term complications and shape treatment recommendations.
Limitations include the retrospective nature of the
study. Furthermore, we included patients who were evaluated by physicians other than otolaryngologists, and
records of thorough ear exams were not available for all
patients. Data collection was further limited because
many patients who had sustained severe trauma with
other intracranial injuries arrived intubated or obtunded.
Finally, follow-up data were limited due to a gross lack of
outpatient follow-up in our patient population.
CONCLUSION
External auditory canal trauma is present in a significant proportion of mandibular and temporal bone
trauma, with an increased incidence in condylar compared to noncondylar trauma. One case was seen with
bilateral EAC fractures despite a unilateral mandibular
fracture. Complications of these fractures can include
hearing loss and canal stenosis; however, additional
Fig. 4. Three-dimensional reconstruction highlighting a right condylar fracture. [Color figure can be viewed in the online issue,
which is available at www.laryngoscope.com.]
Laryngoscope 125: July 2015
Fig. 5. Intraoperative finding: multiple small bone fragments, narrowed canal. Intervention: stented with Xeroform gauze.
External Auditory Canal Fractures: Burchhardt et al.
1581
outpatient follow-up, including hearing examinations, is
still needed to help further elucidate long-term complications and shape treatment recommendations.
BIBLIOGRAPHY
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mandibular trauma]. [Article in German] Chirurg 1977;48:271–273.
2. Akers JO, Narang R, DeChamplain RW. Posterior dislocation of the mandibular condyle into the external ear canal. J Oral Maxillofac Surg
1982;40:369–370.
3. Worthington P. Dislocation of the mandibular condyle into the temporal
fossa. J Maxillofac Surg 1982;10:24–27.
Laryngoscope 125: July 2015
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4. Martis C, Karakasis D. Bleeding from the ear in maxillofacial injuries.
J Maxillofac Surg 1974;2:126–128.
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6. Conover GL, Crammond RJ. Tympanic plate fracture from mandibular
trauma. J Oral Maxillofac Surg 1985;43:292–294.
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Radiol Endod 1998;85:244–247.
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9. Langton SG, Saeed SR, Musgrove BT, Ramsden RT. Deafness and cholesteatoma complicating fracture of the mandibular condyle. Br J Oral
Maxillofac Surg 1996;34:286–288.
External Auditory Canal Fractures: Burchhardt et al.