Case Report

Fatal posterior sternoclavicular Joint dislocation due to occult trauma

Abstract

Posterior sternoclavicular Joint dislocations (PSCJDs) are extremely rare, emergent injuries. We present an unprece- dented case of a 16-year-old boy without any initial history or signs of trauma who died of a brachiocephalic vein laceration secondary to an occult PSCJD. The pathophysiol- ogy, treatment, and diagnosis of PSCJD are discussed.

Posterior (retrosternal) dislocation of the sternoclavicular joint (PSCJD) is a rare injury. Few cases have been reported in the literature since it was first reported in 1824 [1]. By 1922, 20 cases had been published [2]; by 1960, there were

60 [1]; and in 1978, there were only 80 [3]. Even more uncommon are mediastinal injuries from the posteriorly displaced clavicle. These reviews demonstrated mediastinal complications secondary to PSCJD in 27% to 43% of the cases [1,4]. Complications have been published in dozens of case reports and include tracheal compression, laceration, or fistula; mammary artery laceration; aortic compression; superior vena cava compression or laceration; pulmonary artery laceration; subclavian vein and artery compression; brachiocephalic (innominate) artery compression, laceration, and hemorrhagic fistula formation; brachiocephalic vein compression and laceration; cervical root compression; hemothorax; and pneumothorax. Only 4 of these reported cases were fatal [2,5-7].

We present the unfortunate experience of a 16-year-old boy who sustained a PSCJD that resulted in a fatal right brachiocephalic vein transection and hemothorax. There are 12 reported cases of brachiocephalic vein injury secondary to PSCJD, 10 involving brachiocephalic vein compression [1,5,8-15] and 2 cases of laceration [6,16]. Only one resulted in death due to a brachiocephalic laceration because of a PSCJD: a Canadian army dispatch rider at Njimegan, Netherlands, in 1944 [1,6]. (This case was referenced only as a personal communication, and its details are not available for review.)

A 16-year-old boy became unresponsive and had seizure- like activity at his school. Upon arrival, paramedics noted that the patient was disoriented, diaphoretic, and combative. A glucose check showed a level of 104 mg/dL. En route to

the emergency department, the patient became apneic and bradycardic. Bag-valve-mask ventilation with an oral airway was initiated, but the patient quickly deteriorated to an asystolic cardiac arrest. Cardiopulmonary resuscitation was initiated and an endotracheal tube was placed. The patient converted to a pulseless electrical activity arrest.

In the emergency department, cardiopulmonary resuscita- tion continued and appropriate endotracheal tube placement was confirmed by direct laryngoscopy. The patient had good bilateral breath sounds on bag ventilation. The pupils were fixed at 5 mm and nonreactive. Physician examination was otherwise unremarkable, with no signs of trauma. The patient underwent a full medical resuscitation without success. Needle thoracostomies were placed in case pleural decom- pression was necessary. Organized Cardiac activity was seen by ultrasound periodically throughout the resuscitation, but the patient remained pulseless. Eventually, cardiac activity ceased, asystole was confirmed in multiple leads, and the patient was pronounced dead. The total time of the resuscitation was 45 minutes.

The patient underwent a postmortem examination by the county’s Medical Examiner‘s office. On autopsy, the skin of the chest was reflected and the pathologist discovered that the right clavicle easily displaced posteriorly. When displaced, the head of the clavicle met the right brachioce- phalic vein at a point where a complete laceration of the vein was discovered (Fig. 1). After the chest plate was removed, a right hemothorax was discovered as well. The medical examiner’s report determined that the cause of death was a right hemothorax due to a laceration of the right brachioce- phalic vein due to a posterior dislocation of the right sternoclavicular joint (SCJ). The medical examiner’s office noted no signs of external injury at the head, neck, chest, back, or extremities.

Postmortem investigation revealed that classmates had witnessed the patient engaging in “mutual horseplay.” While wrestling, the patient had fallen to the ground, shoulder first, with his friend on top of the contralateral shoulder. The patient had no known history of seizures.

The SCJ is stabilized by 4 ligaments: the anterior and posterior sternoclavicular ligaments, the interclavicular ligament, and the costoclavicular ligament (Fig. 2). Because the posterior sternoclavicular ligament is more robust than the anterior sternoclavicular ligament, 95% of dislocations are anterior [17]. Three grades exist for SCJ injuries: grade I

0735-6757/$ - see front matter (C) 2010

Fig. 1 Blood at the right anterior chest skeletal muscles, which tracks into the right side of the neck. Photograph courtesy of Karen Sullivan MD, Fulton County Medical Examiners Office.

Fig. 3 Ultrasound of dislocated SCJ using high-frequency linear array probe. M indicates manubrium; C, clavicle; B, blood collecting within periosteum. Reprinted from Benson et al [22] in the Joumal of Ultrasound in Medicine with permission from the American Institute of Ultrasound in Medicine.

injuries are sprains caused by stretching of the aforemen- tioned ligaments, grade II injuries are subluxations caused by tearing of all the aforementioned ligaments except for the costoclavicular ligament, and grade III injuries are disloca- tions that result from complete rupture of all 4 ligaments. However, fusion of the medial clavicular epiphysis is incomplete before age 25 years. Therefore, most consider dislocations in patients younger than 25 years to be Salter- Harris type I fractures. Rockwood [18] notes that in some cases, the medial end of the clavicle’s metaphysis comes out of its periosteum and displaces posteriorly, leaving the epiphysis and the medial periosteum in its normal position. In these cases, the sternoclavicular and costoclavicular ligaments are not necessarily torn.

Although direct trauma to the chest can result in dislocation, about 70% of dislocations are the result of lateral compressive forces at the shoulder [19]. When

posterolateral force is applied to a shoulder, the medial clavicle is forced to pivot posteriorly about the costoclavi- cular ligament, which acts as a fulcrum. When anterolateral force is applied to a shoulder, the medical clavicle is forced to pivot anteriorly about the costoclavicular ligament.

The proportion of SCJ dislocations with mediastinal complications has risen over recent decades. This may be secondary to reporting bias as uncomplicated PSCJDs have already been well described. Or it may be due to detection bias as computed tomography (CT), a more sensitive imaging modality, has become popular over recent decades. Nevertheless, in a review of 30 cases of PSCJD, an incorrect Initial diagnosis was made in 50% of the cases [4].

Routine x-rays of the chest and shoulder are often unhelpful because of the surrounding superimposing bones [20]. Several dedicated clavicle projections, including the serendipity, Hobbs, Heinig, and Kattan projections, have

Fig. 2 Sternoclavicular articulation-anterior view. Reprinted from Anatomy of the Human Body by H. Gray with permission from Bartleby.com.

been proposed. Because it can evaluate damage to surrounding tissues and vessels, CT scanning is a more sensitive test.

Once diagnosed, there are several options to reduce the posterior dislocation. In cases where the esophagus, trachea, lung, or great vessels may be lacerated or compressed, reduction becomes emergent. Ideally, reduction should take place in the operating room under general anesthesia because of the risk of vascular or tracheal tear [19]. However, closed reductions have been successfully performed under con- scious sedation in the emergency department as well. Treatment options are as follows:

1. Closed reduction with traction only-traditionally, reductions have been described with the patient lying supine with a bolster between the scapulae. The arm on the injured side is abducted to 90? and extended to 20? while lateral traction is applied at the arm. Buckerfield and Castle [21] discuss an alternative method of reduction in which the arm on the affected side is adducted to the trunk and traction is applied to the arm caudally while anterior-posterior pressure is applied at the shoulders bilaterally. This latter technique yielded a reduction in 6 of 6 patients with posterior dislocations, 3 of whom failed the classic reduction technique.
2. Closed reduction with clavicular manipulation-either of the above techniques of closed reduction is used. In addition, the sterilely prepared clavicle is grasped with towel clips and anterolateral traction is applied.
3. open reduction performed in the operating room.

In one reported case of traumatic PSCJD, an unstable patient had his lacerated brachiocephalic vein and mammary artery repaired via thoracotomy [16]. If proceeding to the operating room for a sternotomy is not possible, access to the great vessels in an unstable patient with PSCJD may require a thoracotomy.

How could we have diagnosed an occult PSCJD in an unresponsive, unstable patient? Physical examination alone is unreliable because hematoma formation at the site of the displaced clavicle may obscure an otherwise expected depression. In addition, the postmortem examination revealed a displaceable clavicle which may have self- reduced after the initial trauma. Given the rarity of this injury, it is obvious that a high index of suspicion is required. Bedside ultrasound may also be used to help diagnose PSCJD if the diagnosis is considered. Ultrasound has been reported to detect abnormal articulation of the SCJ, hematoma secondary to traumatic PSCJD, and exclusion of vascular compression [22,23]. It has also been used for intraoperative evaluation of PSCJD reduction [22,24]. To sonographically evaluate the SCJ, a high-frequency (7-13 MHz) linear-array probe is placed parallel to the long axis of the clavicle [25]. The probe should be moved medially along the clavicle until the sternum is identified. A small,

hypoechoic area should be identified between the clavicle and sternum; this represents the SCJ space (Fig. 3). Bone contours should be examined for normal, posterior, or anterior orientation of the clavicle with relation to the sternum. Color Doppler flow can also be used to assess vascular flow posterior to the SCJ. Ultrasound may have also been helpful if we had thought to look for a hemothorax during the resuscitation.

Posterior sternoclavicular joint dislocation is a rare, sometimes fatal injury that should be considered a true orthopedic emergency. Reduction should be performed as soon as possible, ideally in an operating room. Attempts to reduce a PSCJD in the emergency department should be accompanied by backup thoracotomy equipment and surgeons, particularly when treating an unstable patient. A high index of suspicion is required to make the often- missed diagnosis of PSCJD. Although CT is the imaging modality of choice, special x-ray views and bedside ultrasound may also be useful diagnostic tools, particularly in the unstable patient.

Acknowledgments

Special thanks to Dr Karen Sullivan, the Fulton County Medical Examiners Office, and Brittney Copeland for providing information necessary to complete this case report.

Mark Fenig MD, MPH Robin Lowman MD Byron P. Thompson MD Philip H. Shayne MD

Department of Emergency Medicine Emory University School of Medicine

Atlanta, GA 30303, USA

doi:10.1016/j.ajem.2009.05.011

References

1. Worman LW, Leagus C. Intrathoracic injury following retrosternal dislocation of the clavicle. J Trauma 1967;7(3):416-23.
2. Greenlee DP. Posterior dislocation of the sternal end of the clavicle. JAMA 1944;125(6):426-8.
3. Gangahar DM, Flogaites T. Retrosternal dislocation of the clavicle producing thoracic outlet syndrome. J Trauma 1978;18(5):369-72.
4. Noda M, Shiraishi H, Mizuno K. Chronic posterior sternoclavicular dislocation causing compression of a subclavian artery. J Shoulder Elbow Surg 1997;6(6):564-9.
5. Southworth SR, Merritt TR. Asymptomatic innominate vein tampo- nade with retromanubrial clavicular dislocation. A case report. Orthop Rev 1988;17(8):789-91.
6. Kennedy JC. Retrosternal dislocation of the clavicle. J Bone Joint Surg Am 1949;31B(1):74.
7. Wasylenko MJ, Busse EF. Posterior dislocation of the clavicle causing fatal tracheoesophageal fistula. Can J Surg 1981;24(6):626-7.
8. Hoekzema N, et al. Posterior sternoclavicular joint dislocation. Can J Surg 2008;51(1):E19-E20.
9. Thomas DP, Davies A, Hoddinott HC. Posterior sternoclavicular dislocations-a diagnosis easily missed. Ann R Coll Surg Engl 1999; 81(3):201-4.
10. Bennett ANea. Posterior sternoclavicular joint dislocation with brachiocephalic vein compression in an elite hockey player. Injury Extra 2006;37:422-4.
11. Buckley BJ, Hayden SR. Posterior sternoclavicular dislocation. J Emerg Med 2008;34(3):331-2.
12. Ege T, et al. Bilateral retrosternal dislocation and hypertrophy of medial clavicular heads with compression to brachiocephalic vein. Int Angiol 2003;22(3):325-7.
13. Ono K, et al. Posterior dislocation of the sternoclavicular joint with obstruction of the innominate vein: case report. J Trauma 1998;44(2): 381-3.
14. Schlegel A. Ein seltener fall von luxation clavicularis retrosternal. Munchen Med Wchnschr 1922;69.
15. Mirza AH, Alam K, Ali A. Posterior sternoclavicular dislocation in a rugby player as a cause of silent vascular compromise: a case report. Br J Sports Med 2005;39(5):e28.
16. Cooper GJ, et al. Posterior sternoclavicular dislocation: a Novel method of external fixation. Injury 1992;23(8):565-6.
17. Rockwood C. Fractures and Dislocations of the Shoulder. In: Green DL, Rockwood CA, editors. Fractures in Adults. Lippincott: Philadelphia; 1984. p. 948.
18. Rockwood C. Fractures and dislocations of the shoulder. In: Green DL, Rockwood CA, editors. Fractures. Lippincott: Philadelphia; 1975.

p. 585-787.

1. Selesnick FH, et al. Retrosternal dislocation of the clavicle. Report of four cases. J Bone Joint Surg Am 1984;66(2):287-91.
2. Cope R. Dislocations of the sternoclavicular joint. Skeletal Radiol 1993;22(4):233-8.
3. Buckerfield CT, Castle ME. Acute traumatic retrosternal dislocation of the clavicle. J Bone Joint Surg Am 1984;66(3):379-85.
4. Benson LS, Donaldson JS, Carroll NC. Use of ultrasound in management of posterior sternoclavicular dislocation. J Ultrasound Med 1991;10(2):115-8.
5. Pollock RC, Bankes MJ, Emery RJ. Diagnosis of retrosternal dislocation of the clavicle with ultrasound. Injury 1996;27(9):670-1.
6. Siddiqui AA, Turner SM. Posterior sternoclavicular joint dislocation: the value of intra-operative ultrasound. Injury 2003;34(6):448-53.
7. Ferri M, et al. Sonographic examination of the acromioclavicular and sternoclavicular joints. J Clin Ultrasound 2005;33(7):345-55.