CASE REPORT occipital condyle, fracture
Occipital Condyle Fracture Presenting as Retropharyngeal Hematoma Reported is the case of a 30-year-old male motorcycle accident victim who was found on plain cervical-spine radiography to have prevertebral softtissue swelling. Although subsequent computed tomography demonstrated no cervical-spine fracture, it did reveal a ,fracture of one occipital condyle. The mechanism, diagnosis, and treatment of occipital condyle fractures are reviewed, as is the ligamentous and fascial anatomy of the cervicocranium. Dissection of fracture hematoma inferiorly along vertically oriented tissue planes is hypothesized as the pathogenesis of our patient's retropharyngea] hematoma. In addition to being a sign of potential cervical-spine injury, post-traumatic prevertebral soft-tissue swelling may also indicate occipital condyle fracture. To avoid overlooking such fractures, compute d tomography undertaken to investigate upper cervicalspine prevertebral soft-tissue swelling .should always include slices up to the level of the basal skull so as to visualize the condyles. [Mariani PJ: Occipital condyle fracture presenting as retropharyngeal hematoma. Ann Emerg Med December 1990;19:1447-1449.]
Peter J Mariani, MD, FACEP Syracuse, New York From the Department of Critical Care and Emergency Medicine, SUNY Health Science Center, Syracuse, New York. Received for publication May 18, 1990. Accepted for publication June 12, 1990. Address for reprints: Peter J Mariani, MD, FACER Critical Care and Emergency Medicine, SUNY Health Science Center, Syracuse, New York 13210.
INTRODUCTION Physicians involved in trauma care are taught that thorough evaluation of the lateral cervical radiograph requires attention to the retrotracheal and retropharyngeal soft tissues.~ Prevertebral hematoma resulting in radiographic soft-tissue density with displacement of normal structures may be the only sign of underlying cervical fracture or ligamentous disruption. Similar radiographic findings may arise from structural or functional conditions unrelated to trauma, such as abscess, tumor, respiration, and deglutition. 2 The case of a patient with a lesser-known cause of prevertebral soft-tissue swelling of direct concern to the traumatologist-occipital condyle fracture of the basal skull - is presented. CASE REPORT A 30-year-old man was transported by ambulance to the emergency department after sustaining a motorcycle accident. He was awake and alert, amnestic for the event, and complaining of severe extremity pain. According to paramedics, he had removed his helmet before their arrival. A Philadelphia collar had been applied to his neck, and Hare traction had been applied to a lower extremity. Vital signs on ED arrival included blood pressure of 100/70 m m Hg; pulse, 83; and respirations, 26. Physical examination of the head, chest, and abdomen was normal. A closed midshaft femoral fracture was clinically apparent. There were deep lacerations about both knees and one elbow. Neurovascular status in all extremities was intact. There were no neurologic deficits. Initial radiographic evaluation included a cross-table lateral cervical radiograph that revealed marked soft-tissue swelling at the C1-2 levels (Figure 1). Additional radiographs revealed open olecranon and tibial fractures, a traumatic arthrotomy of one knee, and the suspected closed femoral fracture. On repeat questioning, the patient denied neck pain but was considerably distracted by pain from his extremity trauma. The neck was not tender to palpation. Supine five-view cervical-spine radiographs revealed no fracture or subluxation. During preparations for orthopedic surgery, the patient under-
19:12 December 1990
Annals of Emergency Medicine
1447/123
CONDYLE FRACTURE Mariani
FIGURE 1. Cross-table lateral cervical radiograph demonstrating prevertebral soft-tissue swelling, most extensive at C1-2. FIGURE 2. Cervical CT through the level of the occipital condyles demonstrating right condylar fracture. Note discontinuity of the rim of the foramen magnum and anterior nasogastric tube displacement, by prevertebral soft-tissue swelling.
went cervical computed tomography (CT) scanning, the results of which were initially reported as negative for fracture. With cervical collar in place, he was intubated in the operating room for general anesthesia and underwent reduction and fixation of his extremity injuries. On re-evaluation of the CT scan, attention was called to an area suspicious for a fracture at the right occipital condyle (Figure 2). A repeat CT scan with coronal reconstruction confirmed this suspicion (Figure 3). A CT scan of the brain was otherwise negative. The patient, still free of n e u r o l o g i c deficit, was s w i t c h e d from a Philadelphia to a two-post collar, which was maintained for the r e m a i n d e r of a 16-day h o s p i t a l course. He remained without neurologic deficit when cervical immobilization was discontinued eight weeks thereafter. 124/1448
DISCUSSION O c c i p i t a l c o n d y l e fractures are thought to occur by three distinct m e c h a n i s m s . The first involves a bursting response to axial loading similar to that of the Jefferson fracture of the atlas. The resultant fractures are comminuted with minimal displacement of fragments and are generally stable. The second variety c o m p r i s e s basilar skull fractures from direct blows to the head with extension into the condylar region. These are also stable fractures, with less likelihood of condylar comminution. The third type occurs when lateral flexion or rotary forces tract the alar ligament and avulse a condylar fragment. Loss of ligamentous support renders these injuries unstable. In this setting, fracture fragment encroachment into the foramen magn u m with brainstem impingement has resulted in fatality. 3 There are 27 cases of fractures of the occipital condyles described in the English literature.3, 4 Plain radiographs usually fail to establish the diagnosis. Proximity of the condyles to the jugular and hypoglossal foramina sometimes gives rise to lower cranial nerve injury in association with the fracture, offering the clinician a diagnostic clue to its presence.4, 5 Because the surgical approach to the area is difficult, in the absence of outright brainstem compression, therapy for these fractures is usually restricted to prolonged neck immobilization. 5 Annals of Emergency Medicine
Prevertebral structures at the level of the occipital condyles include, from posterior to anterior, the anterior atlanto-occipital membrane, the p r e v e r t e b r a l fascia, and the buccopharyngeal fascia 6 (Figure 4). Although the prevertebral and retropharyngeal spaces demarcated by these structures are anatomically distinct, they are usually indistinguishable by plain radiography. This accounts for the adjectives "prevertebral" and "retropharyngeal" being interchanged frequently in literature addressing radiographic soft-tissue densities anterior to the cervical spine. The ligaments normally adhere to the anterior bony surfaces of the cervicocranium, producing a concave radiographic contour as they course superiorly. The presence of edema or blood distorts this shape and produces a convex bulge with an obscured margin. 1 As illustrated by our patient, blood may also track down the cervical tissue planes to produce swelling at a site well below that of the injury. Recent reports in the literature have addressed normal standards for and conditions that can affect the cervical prevertebral tissues of the t r a u m a patient.a, z ~l Absent from these articles and from standard trauma texts, however, is acknowledgment that a traumatic hematoma about the cervical spine may arise from a source other than the neck. Similarly, recent articles devoted to 19:12 December 1990
Prevertebra~f--
Atlanto occipital membrane
Apical dental ligament
-
-
fC----
fascia
Prevertebral space
Buccopharyngeal fascia spaceRetr°pharyngeal Anterior longitudinal ligament
o c c i p i t a l c o n d y l e f r a c t u r e s fail to include cervical prevertebral hemat o m a as a p r e s e n t i n g s i g n of t h e injury. 3-5 Because our patient had normal m e n t a l s t a t u s and, w i t h t h e e x c e p t i o n of a m n e s i a , a n o r m a l n e u r o l o g i c examination, cranial CT scan was not planned initially. Rather, CT s c a n of t h e c e r v i c a l s p i n e w a s u n d e r t a k e n to i n v e s t i g a t e s u s p e c t e d i n j u r y to t h i s area a n d led to t h e d i a g n o s i s of s k u l l f r a c t u r e .
SUMMARY T h e c a s e of a p a t i e n t w i t h a n occ i p i t a l c o n d y l e f r a c t u r e is p r e s e n t e d . The diagnosis was made on workup of r e t r o p h a r y n g e a l s o f t - t i s s u e s w e l l i n g n o t e d o n c e r v i c a l - s p i n e radiograp h y . It is n o t g e n e r a l l y k n o w n t h a t such fractures may result in prever: tebral hematoma; therefore, occipital c o n d y l e f r a c t u r e s h o u l d b e a d d e d to t h e d i f f e r e n t i a l d i a g n o s i s of p o s t traumatic radiographic prevertebral
19:12 December 1990
\
4
cervical soft-tissue swelling. CT s c a n n i n g is u s u a l l y r e q u i r e d to e s t a b lish the diagnosis. When undertaken to e v a l u a t e t h e u p p e r c e r v i c a l spine, scan cuts should always reach the l e v e l of t h e b a s a l s k u l l so t h a t i n j u ries t o t h e o c c i p i t a l c o n d y l e s w i l l n o t be overlooked.
F I G U R E 3. C T of the occipital con-
REFERENCES
space: A review of the anatomy, pathology, and clinical presentation. J Otolaryngol 1978;7: 528-536. 7. Penning L: Prevertebral hematoma in cervical spine injury: Incidence and etiologic significance. Am J Radiol 1981;136:553-561. 8. Miles KA, Finlay D: Is prevertebral soft tissue swelling a useful sign in injury of the cervical spine? Injury 1988;19:177-179. 9. Templeton PA, Young JWR, Mirvis SE, et al: The value of retropharyngeal soft tissue measurements in trauma of the adult cervical spine. Skeletal Radiol 1987;16:98-104. 10. Myssiorek D, Shalmi C: Traumatic retropharyngeal hematoma. Arch Otolaryngol 1989; 115:1130-1132. 11. Smith JP, Morrissey P, Hemmick RS, et al: RetropharyngeaI hematomas. J Trauma 1988; 28:553-554.
1. Harris JH, Edeiken-Monroe B: The Radio)ogy of Cervical Spine Trauma. Baltimore, Williams & Wilkins, 1987. 2. Martinez JA, Timberlake GA, Jones JC, et al: Factors affecting the cervical prevertebral space in the trauma patient. Am J Emerg Med 1988; 6:268-272. 3. Anderson PA, Montesano PX: Morphology and treatment of occipital condyle fractures. Spine 1988;13:731-736. 4. Sanjay DS, Coumas JM, Danylevich A, et al: Fracture of the occipital condyle: Case report and review of the literature. J Trauma 1990;30: 240-241. 5. Spencer JA, Yeakley JW, Kaufman HH: Fracture of the occipital condyle. Neurosurgery 1984;15:101-103. 6. Wong YK, Novomy GM: Retropharyngeal
Annals of Emergency Medicine
dyles w i t h coronal r e c o n s t r u c t i o n detailing right condylar fracture. 4. S c h e m a t i c of ]igamentous and fascia] elements of the cervieoeranium.
FIGURE
1449/125
Occipital Condyle Fracture Presenting as Retropharyngeal Hematoma Reported is the case of a 30-year-old male motorcycle accident victim who was found on plain cervical-spine radiography to have prevertebral softtissue swelling. Although subsequent computed tomography demonstrated no cervical-spine fracture, it did reveal a ,fracture of one occipital condyle. The mechanism, diagnosis, and treatment of occipital condyle fractures are reviewed, as is the ligamentous and fascial anatomy of the cervicocranium. Dissection of fracture hematoma inferiorly along vertically oriented tissue planes is hypothesized as the pathogenesis of our patient's retropharyngea] hematoma. In addition to being a sign of potential cervical-spine injury, post-traumatic prevertebral soft-tissue swelling may also indicate occipital condyle fracture. To avoid overlooking such fractures, compute d tomography undertaken to investigate upper cervicalspine prevertebral soft-tissue swelling .should always include slices up to the level of the basal skull so as to visualize the condyles. [Mariani PJ: Occipital condyle fracture presenting as retropharyngeal hematoma. Ann Emerg Med December 1990;19:1447-1449.]
Peter J Mariani, MD, FACEP Syracuse, New York From the Department of Critical Care and Emergency Medicine, SUNY Health Science Center, Syracuse, New York. Received for publication May 18, 1990. Accepted for publication June 12, 1990. Address for reprints: Peter J Mariani, MD, FACER Critical Care and Emergency Medicine, SUNY Health Science Center, Syracuse, New York 13210.
INTRODUCTION Physicians involved in trauma care are taught that thorough evaluation of the lateral cervical radiograph requires attention to the retrotracheal and retropharyngeal soft tissues.~ Prevertebral hematoma resulting in radiographic soft-tissue density with displacement of normal structures may be the only sign of underlying cervical fracture or ligamentous disruption. Similar radiographic findings may arise from structural or functional conditions unrelated to trauma, such as abscess, tumor, respiration, and deglutition. 2 The case of a patient with a lesser-known cause of prevertebral soft-tissue swelling of direct concern to the traumatologist-occipital condyle fracture of the basal skull - is presented. CASE REPORT A 30-year-old man was transported by ambulance to the emergency department after sustaining a motorcycle accident. He was awake and alert, amnestic for the event, and complaining of severe extremity pain. According to paramedics, he had removed his helmet before their arrival. A Philadelphia collar had been applied to his neck, and Hare traction had been applied to a lower extremity. Vital signs on ED arrival included blood pressure of 100/70 m m Hg; pulse, 83; and respirations, 26. Physical examination of the head, chest, and abdomen was normal. A closed midshaft femoral fracture was clinically apparent. There were deep lacerations about both knees and one elbow. Neurovascular status in all extremities was intact. There were no neurologic deficits. Initial radiographic evaluation included a cross-table lateral cervical radiograph that revealed marked soft-tissue swelling at the C1-2 levels (Figure 1). Additional radiographs revealed open olecranon and tibial fractures, a traumatic arthrotomy of one knee, and the suspected closed femoral fracture. On repeat questioning, the patient denied neck pain but was considerably distracted by pain from his extremity trauma. The neck was not tender to palpation. Supine five-view cervical-spine radiographs revealed no fracture or subluxation. During preparations for orthopedic surgery, the patient under-
19:12 December 1990
Annals of Emergency Medicine
1447/123
CONDYLE FRACTURE Mariani
FIGURE 1. Cross-table lateral cervical radiograph demonstrating prevertebral soft-tissue swelling, most extensive at C1-2. FIGURE 2. Cervical CT through the level of the occipital condyles demonstrating right condylar fracture. Note discontinuity of the rim of the foramen magnum and anterior nasogastric tube displacement, by prevertebral soft-tissue swelling.
went cervical computed tomography (CT) scanning, the results of which were initially reported as negative for fracture. With cervical collar in place, he was intubated in the operating room for general anesthesia and underwent reduction and fixation of his extremity injuries. On re-evaluation of the CT scan, attention was called to an area suspicious for a fracture at the right occipital condyle (Figure 2). A repeat CT scan with coronal reconstruction confirmed this suspicion (Figure 3). A CT scan of the brain was otherwise negative. The patient, still free of n e u r o l o g i c deficit, was s w i t c h e d from a Philadelphia to a two-post collar, which was maintained for the r e m a i n d e r of a 16-day h o s p i t a l course. He remained without neurologic deficit when cervical immobilization was discontinued eight weeks thereafter. 124/1448
DISCUSSION O c c i p i t a l c o n d y l e fractures are thought to occur by three distinct m e c h a n i s m s . The first involves a bursting response to axial loading similar to that of the Jefferson fracture of the atlas. The resultant fractures are comminuted with minimal displacement of fragments and are generally stable. The second variety c o m p r i s e s basilar skull fractures from direct blows to the head with extension into the condylar region. These are also stable fractures, with less likelihood of condylar comminution. The third type occurs when lateral flexion or rotary forces tract the alar ligament and avulse a condylar fragment. Loss of ligamentous support renders these injuries unstable. In this setting, fracture fragment encroachment into the foramen magn u m with brainstem impingement has resulted in fatality. 3 There are 27 cases of fractures of the occipital condyles described in the English literature.3, 4 Plain radiographs usually fail to establish the diagnosis. Proximity of the condyles to the jugular and hypoglossal foramina sometimes gives rise to lower cranial nerve injury in association with the fracture, offering the clinician a diagnostic clue to its presence.4, 5 Because the surgical approach to the area is difficult, in the absence of outright brainstem compression, therapy for these fractures is usually restricted to prolonged neck immobilization. 5 Annals of Emergency Medicine
Prevertebral structures at the level of the occipital condyles include, from posterior to anterior, the anterior atlanto-occipital membrane, the p r e v e r t e b r a l fascia, and the buccopharyngeal fascia 6 (Figure 4). Although the prevertebral and retropharyngeal spaces demarcated by these structures are anatomically distinct, they are usually indistinguishable by plain radiography. This accounts for the adjectives "prevertebral" and "retropharyngeal" being interchanged frequently in literature addressing radiographic soft-tissue densities anterior to the cervical spine. The ligaments normally adhere to the anterior bony surfaces of the cervicocranium, producing a concave radiographic contour as they course superiorly. The presence of edema or blood distorts this shape and produces a convex bulge with an obscured margin. 1 As illustrated by our patient, blood may also track down the cervical tissue planes to produce swelling at a site well below that of the injury. Recent reports in the literature have addressed normal standards for and conditions that can affect the cervical prevertebral tissues of the t r a u m a patient.a, z ~l Absent from these articles and from standard trauma texts, however, is acknowledgment that a traumatic hematoma about the cervical spine may arise from a source other than the neck. Similarly, recent articles devoted to 19:12 December 1990
Prevertebra~f--
Atlanto occipital membrane
Apical dental ligament
-
-
fC----
fascia
Prevertebral space
Buccopharyngeal fascia spaceRetr°pharyngeal Anterior longitudinal ligament
o c c i p i t a l c o n d y l e f r a c t u r e s fail to include cervical prevertebral hemat o m a as a p r e s e n t i n g s i g n of t h e injury. 3-5 Because our patient had normal m e n t a l s t a t u s and, w i t h t h e e x c e p t i o n of a m n e s i a , a n o r m a l n e u r o l o g i c examination, cranial CT scan was not planned initially. Rather, CT s c a n of t h e c e r v i c a l s p i n e w a s u n d e r t a k e n to i n v e s t i g a t e s u s p e c t e d i n j u r y to t h i s area a n d led to t h e d i a g n o s i s of s k u l l f r a c t u r e .
SUMMARY T h e c a s e of a p a t i e n t w i t h a n occ i p i t a l c o n d y l e f r a c t u r e is p r e s e n t e d . The diagnosis was made on workup of r e t r o p h a r y n g e a l s o f t - t i s s u e s w e l l i n g n o t e d o n c e r v i c a l - s p i n e radiograp h y . It is n o t g e n e r a l l y k n o w n t h a t such fractures may result in prever: tebral hematoma; therefore, occipital c o n d y l e f r a c t u r e s h o u l d b e a d d e d to t h e d i f f e r e n t i a l d i a g n o s i s of p o s t traumatic radiographic prevertebral
19:12 December 1990
\
4
cervical soft-tissue swelling. CT s c a n n i n g is u s u a l l y r e q u i r e d to e s t a b lish the diagnosis. When undertaken to e v a l u a t e t h e u p p e r c e r v i c a l spine, scan cuts should always reach the l e v e l of t h e b a s a l s k u l l so t h a t i n j u ries t o t h e o c c i p i t a l c o n d y l e s w i l l n o t be overlooked.
F I G U R E 3. C T of the occipital con-
REFERENCES
space: A review of the anatomy, pathology, and clinical presentation. J Otolaryngol 1978;7: 528-536. 7. Penning L: Prevertebral hematoma in cervical spine injury: Incidence and etiologic significance. Am J Radiol 1981;136:553-561. 8. Miles KA, Finlay D: Is prevertebral soft tissue swelling a useful sign in injury of the cervical spine? Injury 1988;19:177-179. 9. Templeton PA, Young JWR, Mirvis SE, et al: The value of retropharyngeal soft tissue measurements in trauma of the adult cervical spine. Skeletal Radiol 1987;16:98-104. 10. Myssiorek D, Shalmi C: Traumatic retropharyngeal hematoma. Arch Otolaryngol 1989; 115:1130-1132. 11. Smith JP, Morrissey P, Hemmick RS, et al: RetropharyngeaI hematomas. J Trauma 1988; 28:553-554.
1. Harris JH, Edeiken-Monroe B: The Radio)ogy of Cervical Spine Trauma. Baltimore, Williams & Wilkins, 1987. 2. Martinez JA, Timberlake GA, Jones JC, et al: Factors affecting the cervical prevertebral space in the trauma patient. Am J Emerg Med 1988; 6:268-272. 3. Anderson PA, Montesano PX: Morphology and treatment of occipital condyle fractures. Spine 1988;13:731-736. 4. Sanjay DS, Coumas JM, Danylevich A, et al: Fracture of the occipital condyle: Case report and review of the literature. J Trauma 1990;30: 240-241. 5. Spencer JA, Yeakley JW, Kaufman HH: Fracture of the occipital condyle. Neurosurgery 1984;15:101-103. 6. Wong YK, Novomy GM: Retropharyngeal
Annals of Emergency Medicine
dyles w i t h coronal r e c o n s t r u c t i o n detailing right condylar fracture. 4. S c h e m a t i c of ]igamentous and fascia] elements of the cervieoeranium.
FIGURE
1449/125
