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Radiology Case. 2012 Mar; 6(3):24-31
Emergency Radiology: Cadaveric position of unilateral vocal cord: a case of cricoid fracture with ipsilateral
arytenoid dislocation
Gopalakrishnan et al.
Journal of Radiology Case Reports
www.RadiologyCases.com
24
Cadaveric position of unilateral vocal cord: a case of
cricoid fracture with ipsilateral arytenoid dislocation
Nirmalkumar Gopalakrishnan1*, Kalaichezhian Mariappan1, Venkatraman Indiran1,
Prabakaran Maduraimuthu1, Chandrasekhar Varadarajan1
1. Department of Radiology, Sree Balaji Medical College and Hospital, Chennai, Tamilnadu, India
* Correspondence: Nirmalkumar Gopalakrishnan, Plot No - 3, Easwari Nagar Extension, East Tambaram, Chennai - 600 059,
Tamilnadu, India
( drgnirmal@yahoo.co.in)
Radiology Case. 2012 Mar; 6(3):24-31 :: DOI: 10.3941/jrcr.v6i3.924
ABSTRACT
We report a case of cricoid cartilage fracture with unilateral arytenoid
dislocation following a motorcycle accident. This 25 year old male sustained
blunt injury to the head, face and neck. He presented late to the hospital with
one week history of dysphonia. Laryngoscopy revealed cadaveric position of
the non-functioning left vocal cord. CT and MRI showed laterally displaced
left vocal cord. Displaced fractures were noted in the cricoid at the junction
of lamina with the anterior arch on the left side and at the right side of the
anterior arch, along with dislocated left arytenoid resulting in ipsilateral
vocal cord palsy. Medialization thyroplasty was performed to improve his
phonation. Laryngeal trauma warrants close monitoring because of the risk
of airway compromise. Radiologists play a crucial role in early diagnosis and
should always have high index of suspicion. Recognition of laryngeal injury
is important for initial resuscitation as well as for long term airway and vocal
function.
CASE REPORT
A 25 years old male presented to the ENT department
with one week history of dysphonia. He was involved in a
motorcycle accident sustaining abrasions to his forehead, right
side of the chest and was not sure of injuring his neck.
Although upon further questioning he was able to recollect
hitting his neck onto the metal crossbar in the handle of the
lightweight motorcycle. There was no history of loss of
consciousness, vomiting or ear, nose and throat bleeding. On
physical examination, a small non-tender swelling was noted
to the right of the midline on the anterior aspect of the neck
just below the thyroid cartilage prominence.
Video laryngoscopy showed paralyzed left vocal cord
lying in a cadaveric (lateral) position [Fig 1].
Plain radiograph of the cervical spine was essentially
normal [Fig 2]. CT scan of the neck showed displaced
fractures involving the cricoid cartilage [Fig. 3A] at the
junction of the lamina with the anterior arch on the left side
and on the right side of the anterior arch resulting in disruption
of the cricoid ring [Fig. 5A,5B]. Superior displacement of the
left arytenoid was noted suggesting dislocation [Fig. 3B].
Anterior displacement was noted involving the right half
segment of the fractured cricoid ring resulting in a small
swelling noted on physical examination. The left aryepiglottic
fold was thickened [Fig. 4A,6A]. The left vocal cord was
laterally displaced [Fig. 4B]. Rest of the larynx appeared
normal. Contrast-enhanced CT was not contributory.
Arytenoids were not visualized in the MRI scan but it
demonstrated laterally placed left vocal cord, thickening of the
left aryepiglottic fold and cricoid fractures with adjacent
edema [Fig. 7]. He underwent Medialization thyroplasty, a
phonosurgical procedure for voice augmentation.
Laryngeal fractures may be due to blunt or penetrating
injury and can be categorized as either high or low velocity.
DISCUSSION
CASE REPORT
Radiology Case. 2012 Mar; 6(3):24-31
Emergency Radiology: Cadaveric position of unilateral vocal cord: a case of cricoid fracture with ipsilateral
arytenoid dislocation
Gopalakrishnan et al.
Journal of Radiology Case Reports
www.RadiologyCases.com
25
Vocal cord paralysis can be either unilateral or bilateral. It
results from dysfunction of the recurrent laryngeal or the vagus
nerve and from mechanical derangement of the larynx. The
most common cause is surgical iatrogenic injury (44%). Other
causes include malignancies (17%), endotracheal intubation
(15%), neurologic diseases (12%), idiopathic causes (12%),
blunt or penetrating trauma to the neck, viral infection,
inflammation (involving larynx or cricoarytenoid joint),
radiation injury, metabolic causes and toxins [1].
Motor vehicle accidents are the most common cause of
blunt injury. The typical injury mechanism being described is
one where the larynx in a hyper extended neck is compressed
directly against the steering wheel or dashboard or the metal
cross bar in a motorcycle. Other causes of blunt injury include
direct blows sustained during assaults, sport injuries, hanging,
manual strangulation and iatrogenic causes.
Strangulation type injuries typically cause cartilage
fracture without mucosal lacerations. Associated arytenoid
cartilage dislocation and recurrent laryngeal nerve injury can
occur. The clothesline injury is one of the most severe forms
of blunt trauma to the larynx. This occurs when the individual
riding a motorcycle strikes his neck against a stationary object
such as a wire fence or tree limb. This can result in
cricotracheal separation.
Gunshot or knife wounds are the primary causes of
penetrating injuries.
Unilateral vocal fold paralysis results in glottic
incompetence, either partial or complete, resulting in a weak or
absent vocal fold vibration leading to dysphonia.
Laryngeal fracture, a rare potentially life-threatening
injury accounts for <1% of all blunt traumas [2]. Its incidence
varies with the sample size and geographic locality.
Bent et al reported an incidence of 1/5000 emergency
department visits in 1987 for both blunt and penetrating
laryngeal injuries, while Schaefer reported an incidence of
1/30 000 emergency department visits over a 27-year period
for blunt injuries alone [3,4]. Jewett et al in their series
reported the incidence of external laryngeal trauma as 1 per
137 000 inpatient visits and noted that males (77% vs 33%)
were more prone for traumatic laryngeal injuries [5]. The
associated mortality rate with this injury is about 2% [5].
Females with slender, long neck are highly susceptible to
laryngeal injury, particularly in supraglottic region.
Isolated cricoid injury accounts for less than 50% of all
laryngeal traumas [6].
Arytenoid dislocation and arytenoid subluxation are
extremely rare. It results in reduced mobility of the true vocal
fold and incomplete glottic closure mimicking true vocal fold
paralysis. Its incidence is not known. About 104 cases of
arytenoid dislocation have been reported in literature, based on
a contemporary literature review by Norris BK et al on
arytenoid dislocation in January 2011 [7]. Arytenoid
dislocations are reported to occur in 0.1% of tracheal
intubations [8]. There is no age or sex predilection.
Associated anomalies like laryngomalacia, acromegaly etc can
weaken the cricoarytenoid joint.
Intubation trauma is the most common etiology for
arytenoid subluxation. Blunt and penetrating neck trauma is
less common causes [8].
Clinical presentation is common to arytenoid
subluxation/dislocation and vocal fold paralysis. Reduced
vocal fold mobility, arytenoid edema and loss of arytenoid
symmetry are the signs noted upon laryngoscopy in acute
arytenoid subluxation [9]. Poor glottic closure and
malalignment of the true vocal folds are often noted.
CT scan is the technique of choice for evaluating larynx.
Until now, MRI has not been shown to be superior to CT scan
in evaluating the arytenoid-cricoid interface and other
laryngeal structures.
Typical CT scan findings of arytenoid subluxation include
displacement of the arytenoid body, altered angulation of the
aryepiglottic fold and widening of the ventricle on the affected
side [10]. Patients with vocal cord paralysis may demonstrate a
slight rotation and displacement of the arytenoid, but not to the
degree that is evident with arytenoid subluxation/dislocation.
Visualization of the laryngeal cartilages by CT scan is
limited by the degree of mineralization, especially in paediatric
population.
In our case, CT scan shows superior displacement with
rotation of the left arytenoid and thickening of the left
aryepiglottic fold (Fig. 3B,4A), features consistent with
arytenoid dislocation.
Anatomically the larynx is guarded by the mandible,
sternum, sternocleidomastoid muscles (aiding neck flexion)
and the rigid cervical spine posteriorly accounting for the
rarity of this injury. All muscles of the larynx are supplied by
the recurrent laryngeal nerve except cricothyroid which is
innervated by the external laryngeal nerve.
With complete recurrent laryngeal nerve paralysis the
vocal cord takes up a paramedian position. With complete
paralysis of both the recurrent laryngeal nerve and the external
laryngeal nerve the vocal cords takes a more lateral cadaveric
position which is also seen with arytenoid dislocation [11].
The differential diagnosis for acute unilateral vocal fold
paralysis includes recent upper respiratory tract viral infection
and recent intubation for any surgical procedure.
In our case, the left vocal cord assumes a lateral cadaveric
position (Fig. 4B,7A,7B) making both arytenoid dislocation
and paralysis of both the recurrent laryngeal nerve and the
external laryngeal nerve (external branch of the superior
laryngeal nerve) as the differentials. But it is highly unlikely
for both the nerves to be paralyzed in this scenario. With
history of blunt injury to the neck and CT examination
demonstrating left arytenoid dislocation, we believe left
arytenoid dislocation as the cause for left vocal cord paralysis
in this case.
Radiology Case. 2012 Mar; 6(3):24-31
Emergency Radiology: Cadaveric position of unilateral vocal cord: a case of cricoid fracture with ipsilateral
arytenoid dislocation
Gopalakrishnan et al.
Journal of Radiology Case Reports
www.RadiologyCases.com
26
Medical management has little role in the treatment of
patients with unilateral vocal fold paralysis. Surgery includes
temporary or permanent procedure aimed at restoring glottic
competence. Temporary measures include endoscopic vocal
fold injections while permanent treatment includes procedures
like laryngeal framework surgery, medialization laryngoplasty
(type 1 thyroplasty) and arytenopexy [12, 13].
Our patient underwent medialization thyroplasty. This
procedure is ideally performed under local infiltration
anesthesia wherein the paralyzed vocal cord is surgically
medialized in an attempt to improve the phonation [14].
High index of suspicion and early recognition is crucial in
the management of patients with cricoid cartilage fracture and
arytenoid dislocation. Of various imaging modalities, laryngeal
skeleton, especially the cartilages are best studied by CT
imaging.
1. Benninger MS, Gillen JB, Altman JS. Changing etiology of
vocal fold immobility. Laryngoscope. Sep
1998;108(9):1346-50. PMID: 9738754
2. Fuhrman GM, Stieg FH 3rd, Buerk CA. Blunt laryngeal
trauma: classification and management protocol. J Trauma.
Jan 1990;30(1):87-92. PMID: 2296072
3. Bent JP 3rd, Silver JR, Porubsky ES. Acute laryngeal
trauma: a review of 77 patients. Otolaryngol Head Neck
Surg. Sep 1993;109(3 Pt 1):441-9. PMID: 8414560
4. Schaefer SD, Brown OE. Selective application of CT in the
management of laryngeal trauma. Laryngoscope. Nov
1983;93(11 Pt 1):1473-5. PMID: 6415356
5. Jewett BS, Shockley WW, Rutledge R. External laryngeal
trauma analysis of 392 patients. Arch Otolaryngol Head
Neck Surg. Aug 1999;125(8):877-80. PMID: 10448735
6. Oh JH, Min HS, Park TU, et al. Isolated cricoid fracture
associated with blunt neck trauma. Emerg Med J. Jul
2007;24(7):505-6. PMID: 17582051
7. Norris BK, Schweinfurth JM. Arytenoid dislocation: An
analysis of the contemporary literature. Laryngoscope. 2011
Jan; 121(1):142-6. PMID: 21181984
8. Yamanaka H, Hayashi Y, Watanabe Y, Uematu H,
Mashimo T. Prolonged hoarseness and arytenoid cartilage
dislocation after tracheal intubation. Br J Anaesth. Sep
2009;103 (3):452-5. PMID: 19556269
9. Hoffman HT, Brunberg JA, Winter P, et al. Arytenoid
subluxation: diagnosis and treatment. Ann Otol Rhinol
Laryngol. Jan 1991;100(1):1-9. PMID: 1985521
10. Alexander AE Jr, Lyons GD, Fazekas-May MA, et al.
Utility of helical computed tomography in the study of
arytenoid dislocation and arytenoids subluxation. Ann Otol
Rhinol Laryngol. Dec 1997;106(12):1020-3. PMID:
9415597
11. Schroeder U, Motzko M, Wittekindt C, Eckel HE.
Hoarseness after laryngeal blunt trauma: a differential
diagnosis between an injury to the external branch of the
superior laryngeal nerve and an arytenoid subluxation. A
case report and literature review. Eur Arch
Otorhinolaryngol. Jul 2003;260(6):304-7. PMID: 12883952
12. Hamdan AL, Mokarbel R, Dagher W. Medialization
laryngoplasty for the treatment of unilateral vocal cord
paralysis: a perceptual, acoustic and stroboscopic
evaluation. J Med Liban. 2004 Jul-Sep; 52(3):136-41.
PMID: 16432970
13. Isshiki N. et al. Thyroplasty as a new phonosurgical
technique. Acta Otolaryng 78: 451-7, 1974. PMID: 4451096
14. Netterville JL, Stone RE, Luken ES, Civantos FJ, Ossoff
RH. Silastic medialization and arytenoid adduction: the
Vanderbilt experience. A review of 116 phonosurgical
procedures. Ann Otol Rhinol Laryngol. 1993
Jun;102(6):413-24. PMID: 8390215
REFERENCES
TEACHING POINT
TEACHING POINT
Radiology Case. 2012 Mar; 6(3):24-31
Emergency Radiology: Cadaveric position of unilateral vocal cord: a case of cricoid fracture with ipsilateral
arytenoid dislocation
Gopalakrishnan et al.
Journal of Radiology Case Reports
www.RadiologyCases.com
27
Figure 1: 25 year old male with cricoid fractures and dislocated left arytenoid causing ipsilateral vocal cord paralysis. Video
laryngoscopy images shows paralyzed left vocal cord lying in a cadaveric (lateral) position.
Figure 2 (left): 25 year old male with cricoid fractures and
dislocated left arytenoid causing ipsilateral vocal cord
paralysis. Plain radiograph lateral projection of the cervical
spine shows no abnormality.
FIGURES
Radiology Case. 2012 Mar; 6(3):24-31
Emergency Radiology: Cadaveric position of unilateral vocal cord: a case of cricoid fracture with ipsilateral
arytenoid dislocation
Gopalakrishnan et al.
Journal of Radiology Case Reports
www.RadiologyCases.com
28
Figure 3: 25 year old male with cricoid fractures and dislocated left arytenoid causing ipsilateral vocal cord paralysis. 3A)
Contrast-enhanced CT axial section of the neck (bone window) shows cricoid fracture involving the anterior aspect on the right
side (thin arrow) and at the junction of lamina with the arch on the left side (thick arrow). Fracture fragments appear displace d.
3B) Contrast-enhanced CT axial section of the neck (bone window) shows dislocated left arytenoid displaced superiorly (arrow)
(Hitachi Eclos 8 slice CT scanner; Protocol: 250 mAs, 120kV, 2.5mm slice thickness)
Figure 4: 25 year old male with cricoid fractures and dislocated left arytenoid causing ipsilateral vocal cord paralysis. 4A)
Contrast-enhanced CT axial section of the neck shows thickened left aryepiglottic fold (arrow). 4B) Contrast-enhanced CT axial
section of the neck shows laterally displaced left vocal cord (arrow) (Hitachi Eclos 8 slice CT scanner; Protocol: 250 mAs,
120kV, 2.5mm slice thickness, 50ml of nonionic contrast medium)
Radiology Case. 2012 Mar; 6(3):24-31
Emergency Radiology: Cadaveric position of unilateral vocal cord: a case of cricoid fracture with ipsilateral
arytenoid dislocation
Gopalakrishnan et al.
Journal of Radiology Case Reports
www.RadiologyCases.com
29
Figure 5: 25 year old male with cricoid fractures and dislocated left arytenoid causing ipsilateral vocal cord paralysis. 5A)
Contrast-enhanced CT coronal section (Multi Planar Reconstruction) of the neck shows cricoid fracture (arrow) at the anterior
aspect on right side. 5B) Contrast-enhanced CT coronal section (Multi Planar Reconstruction) of the neck shows cricoid fracture
(arrow) posteriorly at the junction of lamina and arch on the left side. (Hitachi Eclos 8 slice CT scanner; Protocol: 250 mAs,
120kV, 1.2mm slice thickness, 50ml of nonionic contrast medium)
Figure 6 (left): 25 year old male with cricoid fractures and
dislocated left arytenoid causing ipsilateral vocal cord
paralysis. 6A) Plain CT coronal section (Multi Planar
Reconstruction) of the neck shows left aryepiglottic fold
thickening (arrow). (Hitachi Eclos 8 slice CT scanner;
Protocol: 250 mAs, 120kV, 1.2mm slice thickness)
Radiology Case. 2012 Mar; 6(3):24-31
Emergency Radiology: Cadaveric position of unilateral vocal cord: a case of cricoid fracture with ipsilateral
arytenoid dislocation
Gopalakrishnan et al.
Journal of Radiology Case Reports
www.RadiologyCases.com
30
Figure 7: 25 year old male with cricoid fractures and dislocated left arytenoid causing ipsilateral vocal cord paralysis. Hitachi
Aperto 0.4 Tesla MR scanner. 7A) T2 weighted spin echo sequence image (TR=3600; TE=104), coronal section of the neck
shows left vocal cord paralysis (arrow). 7B) T2 weighted spin echo sequence image (TR=6150; TE=100), axial section of the
neck shows non-functioning left vocal cord in cadaveric (lateral) position (arrow). 7C) T2 weighted spin echo sequence image
(TR=6150; TE=100), axial section of the neck shows cricoid fracture (arrow) on the left side at the junction of lamina and the
arch. 7D) T2 weighted spin echo sequence image (TR=6150; TE=100), axial section of the neck shows cricoid fracture (arrow)
anteriorly on the right side.
Radiology Case. 2012 Mar; 6(3):24-31
Emergency Radiology: Cadaveric position of unilateral vocal cord: a case of cricoid fracture with ipsilateral
arytenoid dislocation
Gopalakrishnan et al.
Journal of Radiology Case Reports
www.RadiologyCases.com
31
Conventional
Radiograph
CT
MRI
Arytenoid Dislocation
Essentially normal
Cadaveric position of ipsilateral
vocal cord, Displaced arytenoid,
Ipsilateral aryepiglottic fold
thickening, Widening of
ipsilateral ventricle, Associated
cricoid fracture
Cadaveric position of ipsilateral
vocal cord, Ipsilateral
aryepiglottic fold thickening,
Widening of ipsilateral
ventricle,
Associated cricoid fracture
Nerve injury involving both
recurrent laryngeal nerve
and the external branch of
the superior laryngeal nerve
Findings depend on the
etiology, which is
mostly iatrogenic
surgical trauma.
Findings depend on the etiology,
which is mostly iatrogenic
surgical trauma.
Normal arytenoid cartilages.
Findings depend on the
etiology, which is mostly
iatrogenic surgical trauma.
Normal arytenoid cartilages.
Table 2: Differential table for arytenoid dislocation
Etiology
Blunt trauma - for cricoid fracture and arytenoid dislocation
Arytenoid dislocation - for left vocal cord paralysis
Incidence
Laryngeal fractures - < 1% of all blunt traumas
Arytenoid dislocation - unknown, < 80% has been reported
Gender ratio
Laryngeal fractures - Common in males (77%)
Arytenoid dislocation - No sex predilection
Age predilection
Laryngeal fractures - No sex predilection
Arytenoid dislocation - No sex predilection
Risk factors
Laryngeal fractures - Females with long slender neck
Arytenoid dislocation - laryngomalacia, acromegaly
Treatment
Vocal fold injections, Laryngeal framework surgery, Medialization laryngoplasty, Arytenopexy
Prognosis
Associated with 2% of mortality rate
Findings on imaging
Cricoid cartilage fracture, Left arytenoid dislocation, Laterally placed left vocal cord, Left
aryepiglottic fold thickening, Widening of left ventricle
Table 1: Summary table for blunt injury of larynx with specific reference to arytenoid dislocation
CT - Computed Tomography
ENT - Otorhinolaryngology
MRI - Magnetic Resonance Imaging
TE - Echo time
TR - Repetition time
Cricoid cartilage; arytenoid cartilage; vocal cord paralysis;
thyroplasty
ENT department, Sree Balaji Medical College and Hospital,
Chennai, India
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