Sternoclavicular Joint Injury in Emergency Medicine

Usually only through the application of significant force do the ligaments supporting the SCJ become completely disrupted, enabling dislocation of the joint. Whether the SCJ subluxes or dislocates depends on the extent of the damage to the supporting ligaments and capsule. Sternoclavicular joint injuries (SJIs) are graded into 3 types.

• A first-degree injury, or simple sprain, constitutes an incomplete tear or stretching of the sternoclavicular and costoclavicular ligaments. Discomfort is mild, and no instability is present. This is the most common type of SJI.

• With a second-degree injury, the clavicle undergoes an anterior or posterior subluxation from its manubrial attachment, signifying a complete breach of the sternoclavicular ligament but at most, only a partial tear of the costoclavicular ligament.

• With a third-degree injury, complete rupture of the sternoclavicular and costoclavicular ligaments permits the clavicle to completely dislocate from the manubrium.

A significant direct or indirect force to the shoulder region can cause a traumatic dislocation of the SCJ.[15] Anterior dislocations of the SCJ are much more common (by a 20:1 ratio), usually resulting from an indirect mechanism such as a blow to the anterior shoulder that rotates the shoulder backward and transmits the stress to the joint.[16]  Traumatic contact driving the shoulder forward can cause posterior dislocations of the SCJ, as can direct impact to the superior sternal or medial clavicular surfaces.

The ligaments and capsule of the SCJ contribute enough stability to make this one of the least dislocated joints in the body. Posterior dislocations are considerably less common than anterior dislocations. However, the proportion of reported mediastinal complications seems to have risen. This may be due to either reporting bias or due to detection bias with the increased use of CT scanning and its increased sensitivity.

Mortality/Morbidity

Mortality and significant morbidity occur infrequently with anterior dislocations of the SCJ.[17, 18, 19, 20] Problems are usually related to issues of physical appearance as well as pain and functional limitations for persons with an active lifestyle.

However, a posterior SCJ dislocation (PSCD) has the potential for severe and even life-threatening complications. Neurovascular complications occur in up to 30% of patients with PSCD, with a mortality between 3 and 4%.[21, 22]  Case reports of such complications have included the following:

• Lung injury (eg, hemothroax, pneumothorax)

• Tracheal injury

• Vascular injury, such as compression, laceration, fistula formation, thrombosis, and pseudoaneurysm formation of the adjacent blood vessels (including the aorta, superior vena cava, subclavian artery or vein, brachiocephalic artery or vein, mammary artery, and jugular vein)

• Nerve injury (including cerebrovascular accident, phrenic nerve, and brachial plexus injury)

• Esophageal injury

These and other complications can cause significant disability, including even cerebrovascular accident and death.[17, 18, 23]

Overall incidence of sternoclavicular joint injury is higher in males than in females, probably because of the activities (eg, motor vehicle crash, contact sports) associated with the injury. However, recurrent atraumatic anterior subluxation of the SCJ (usually associated with overall joint laxity), though rare, occurs more frequently in young girls.

In patients younger than age 25 years, a true sternoclavicular separation may not occur. A physeal disruption causing clavicular displacement may present with similar signs and symptoms[24] .

In SCJ injuries, first determine the onset of pain and the mechanism of injury. SCJ dislocations may follow direct trauma to the anteromedial aspect of the clavicle that drives it backward and causes a posterior dislocation. More commonly, dislocations arise from an indirect force applied to the anterolateral or posterolateral shoulder that compresses the clavicle down toward the sternum. The direction the shoulder is driven determines the type of dislocation. When overwhelming compression propels the shoulder forward, the force directed toward the clavicle produces a posterior dislocation of the sternoclavicular joint. If the shoulder is pressed and rotated backward, the force directed down the clavicle produces an anterior dislocation of the SCJ.

(See the images below, all of the same patient.)

This 80-year-old woman presented 1 week after a fall because of persistent pain and discoloration in the anterior part of her chest. Certain movements of her right arm were especially painful though not incapacitating. Note the extensive ecchymosis of the anterior part of her thorax and the swelling of the right upper parasternal/lower anterior neck area. The right sternoclavicular joint area was tender and edematous to palpation.

The right sternoclavicular joint appears edematous on lateral inspection. Palpation confirms the apparent anterior dislocation.

Comparison of the normal left sternoclavicular joint emphasizes the abnormalities.

The patient refused further workup and treatment beyond a temporary sling, stating that the injury had not significantly affected her lifestyle. She was discharged home in the company of her daughter with over-the-counter analgesics.

The presence of hypermobility, such as with Ehlers-Danlos syndrome, can reduce the force necessary for dislocation. Atraumatic SCJ dislocations can occur, though they are rare.

Patients commonly complain of chest and shoulder pain exacerbated by arm movement or by assuming a supine position.[25]

Pain tends to be more severe with posterior dislocations.

Additional symptoms may be caused by associated injuries or by compression of adjacent structures by a posterior SCJ dislocation and may include the following:

• Dyspnea

• Dysphagia

• Paresthesias and neurologic deficits

• Swelling and pain in an upper extremity

Patients typically present with their head tilted toward the affected side and hold the affected arm across the trunk with the uninjured arm.

Check vital signs, especially respirations. Tachypnea, stridor, hoarseness and other signs of respiratory distress (posterior dislocations) may be present, particularly in posterior dislocations. Verify adequacy of circulation. Venous congestion of the head, neck, and/or affected arm may also result from posterior dislocations. Neurologic and vascular deficits may be present.

The affected shoulder usually appears shortened and thrust forward. Generally, edema and tenderness are present over the SCJ. Pain manifests with any range of motion testing that affects the SCJ and becomes more severe when a lateral compressive force is applied to the shoulders.

When viewed from the level of the patient's knees, anterior SCJ dislocations demonstrate a conspicuous asymmetry, with the medial aspect of the affected clavicle appearing prominent. Palpation reveals a medial protrusion.

Physical findings at the SCJ may be more subtle with posterior SCJ dislocations, with swelling and a defect evident on inspection and palpation. The corner of the sternum on the affected side may be palpated more readily than on the noninjured side. Palpation often reveals exquisite tenderness medially. Soft tissue swelling may obscure any defect and create the false impression of an anterior dislocation.

Posterior SCJ dislocations can be associated with potentially life-threatening tracheal, esophageal, vascular, and neurologic injury and may involve the following specific complications[26] :

• Tracheal rupture or erosion

• Pneumothorax or hemothorax

• Thoracic outlet syndrome

• Laceration, compression, or thrombosis of adjacent vascular structures

• Neurologic injury including brachial plexus and cerebrovascular injuries

• Recurrent dislocation

• Residual swelling, deformity and/or decreased range of motion

Routine radiographs of the sternoclavicular joint are often difficult to interpret and may falsely appear normal.[6, 7, 8]

A specialized view, known as the serendipity view and described by Rockwood, may reveal the medial clavicle position.[9] For this technique, the beam is tilted to 40° from vertical and directed cephalad through the manubrium of the patient while in a supine position. Normal clavicles should appear in the same horizontal plane, while anterior and posterior dislocations appear above and below the plane, respectively.[2]

In the Hobbs view, the patient sits at the radiography table and leans forward so that the anterior chest is in contact with the film cassette and the flexed elbows straddle the cassette and support the patient. The x-ray beam is aimed directly down through the cervical spine, projecting the sternoclavicular joints onto the film cassette.

CT scanning is an excellent technique to study problems of the sternoclavicular joint. Request inclusion of both sternoclavicular joints and the medial half of both clavicles on the CT scan so that the injured side can be compared with the noninjured side. In addition to revealing the position of the medial clavicle, the CT scan provides important information about the vital tissues of the superior mediastinum, which may be concomitantly injured.[10]

In a study to assess digital tomography in SCJ pathology, of 102 patients who had digital tomography as their initial investigation, the most common diagnoses identified included osteoarthritis, fracture, and dislocation, and only 18 patients required further investigation by CT or MRI to make the diagnosis.[11]

(See the images below.)

CT scan of a left sternoclavicular dislocation demonstrates anterior and superior displacement of the clavicle from its normal articulation with the manubrium. The right sternoclavicular joint is normal.

CT scan of a left sternoclavicular dislocation demonstrates anterior and superior displacement of the clavicle from its normal articulation with the manubrium. The right sternoclavicular joint is normal.

CT scan of a left sternoclavicular dislocation demonstrates anterior and superior displacement of the clavicle from its normal articulation with the manubrium. The right sternoclavicular joint is normal.

Other imaging studies, such as angiography or esophagoscopy, may be indicated when mediastinal injuries from a posterior dislocation are suspected.

MRI provides similar information as a CT scan while better documenting the soft tissue anatomy and associated mediastinal structures, but availability is often limited for emergency patients. Relative cost is also a consideration.

Bedside ultrasound may be used to evaluate bony contours and structural alignment, and the sternoclavicular joint space, a small hypoechoic area, may be identified between the clavicle and sternum. Adjacent vascular structures and their flow may be assessed, and the presence of a hemothorax or pneumothorax may also be diagnosed. Typically, a high frequency (7-13) MHz linear-array probe is used, aligned parallel to the clavicular long axis.[27, 28]

Patients with posterior SCJ dislocations frequently sustain associated potentially serious injuries that may take treatment precedence over the dislocation.[12] Sprains of the SCJ require only symptomatic treatment (eg, immobilization with a sling, ice for 24-48 hr, analgesics, and anti-inflammatory medications).

Reductions performed in the ED require stabilization of the affected shoulder with a soft figure-of-eight dressing, a commercial clavicular harness, or secure sling. Maintain immobilization for at least 4 weeks.[13, 14]

Anterior

In one study, nonoperative repair for treatment of acute anterior dislocations resulted in good to excellent results in 69% of patients.[29] Interposition of the joint capsule or the ligaments can make the joint irreducible, and maintenance of reduction can be problematic.[30] Once the diagnosis is made, prompt treatment is indicated, since functional outcomes are significantly improved for acute over chronic dislocations. If indicated, carry out closed reduction of an anterior dislocation as follows[31] :

• Place the patient in a supine position on the stretcher.

• Place a 3- to 4-inch thick bolster (rolled sheet or sandbag) between the scapula and spine (to help separate the clavicle from the manubrium).

• Have an assistant abduct (to 90°) and extend (10-15°) the shoulder on the affected side and apply traction.

• If reduction does not occur, apply pressure to the medial clavicle in a posterior and inferior direction.

Treatment options for recurrent/unreduced anterior SCJ dislocations may include open reduction and internal fixation, or acceptance of some degree of permanent instability, depending on the patient's characteristics and functionality.

Closed reduction with conscious sedation or general anesthesia is the preferred initial treatment, but it may not be possible or necessary on an emergent basis. Because of potential associated vascular injury, the operating room may be the more appropriate setting for reduction.

Posterior

Acute posterior dislocations are a more serious injury because of their potential association with other injuries, with symptoms of mediastinal compression present in up to 30%. In one study, closed reduction, with subsequent open reduction after a failed closed attempt, resulted in good to excellent results in 96% of patients.[29] Additional imaging may be necessitated to evaluate the presence of other injuries, and appropriate consultation with additional specialties may be indicated.

Once the diagnosis is made, prompt treatment is indicated because functional outcomes are significantly improved for acute over chronic dislocations. The treatment of associated injuries and/or complications may take priority over the SCJ dislocation. Emergent closed reduction of a posterior dislocation is as follows:[32]

• Place the patient in a supine position on the stretcher.

• Place a 3- to 4-inch thick bolster (rolled sheet or sandbag) between the scapula and spine (to help separate the clavicle from the manubrium).

• Abduct (90°) and extend (10-15°) the shoulder on the affected side and apply traction to the arm as an assistant applies countertraction to the trunk.

• If traction fails to reduce the dislocation, pull the medial clavicle forward while an assistant maintains traction and an abduction force on the affected limb.

• In situations in which the clavicle cannot adequately be grasped by the fingers, use a towel clip to grip the clavicle (after sterile preparation of the skin) and pull forward.

Treatment options for unreduced posterior SCJ dislocations may include open reduction and internal fixation, or acceptance of some degree of permanent instability, depending on the patient's characteristics and functionality. Open operative intervention must be considered for unstable fractures, irreducible fractures, and repair of posteriorly displaced physeal fractures of the medial clavicle.

An alternative technique for reduction of a posterior SCJ dislocation (proposed by Buckerfield and Castle) suggests caudal traction accompanying adduction of the affected arm, along with downward pressure on both shoulders.

Closed reduction attempts for posterior SCJ dislocations may fail or may be associated with complications such as injury to the adjacent mediastinal structures.

Closed reduction may be unsuccessful or not attempted, depending on the age and activity level of the patient. In such patients, an immobilizing sling, analgesics, and anti-inflammatory agents may be used for symptomatic relief.

In a study of skeletally immature patients (12 boys; mean age, 14.8±2.74 yr) with sternoclavicular injuries with posterior displacement, medial clavicular physeal fractures and sternoclavicular dislocations were effectively managed with closed or open reduction. Of the 12 patients, 8 were initially treated with closed reduction, 2 successfully and 6 requiring subsequent open reduction. Four of the 12 patients underwent an immediate open reduction.[33]  

In another study, of the 140 adolescent patients (12-18 yr; mean, 15.24 yr) with posterior sternoclavicular joint injuries, 49 patients (35%) underwent closed treatment only, 42 (30%) open treatment alone, and 47 (33.57%) closed treatment followed by open treatment. Additionally, 55.8% of closed reductions performed within 48 hours were successful, as compared to 30.8% of those performed more than 48 hours after injury.[34]

Inpatient admission may be necessary for patients with posterior SCJ dislocations or for patients in need of treatment of associated injuries.

Patients thought to have sustained additional significant injuries may require transfer to an advanced facility, such as a trauma center.

Issues of patient stability and transfer benefit are best addressed based on the clinical setting and available resources.

Patients with posterior SCJ dislocation and/or potential complications may benefit from transfer to a facility with thoracic, vascular, orthopedic or other specialty consultation services.

The goal of therapy is to reduce inflammation and to minimize severe pain. To achieve this goal, anti-inflammatory agents and analgesics are the drugs of choice (DOCs).

Class Summary

These agents commonly are used for the relief of mild to moderate pain. Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and enable physical therapy regimens. Most analgesics have sedating properties that are beneficial for patients with injuries. Although the effects of NSAIDs in the treatment of pain tend to be patient specific, ibuprofen is usually the DOC for the initial therapy. Other NSAIDs may be considered.

Propoxyphene products were withdrawn from the United States market on November 19th, 2010. The withdrawal was based on new data showing QT prolongation at therapeutic doses. For more information, see the FDA MedWatch safety information.

Ibuprofen (Motrin, Advil, NeoProfen, Provil, Dyspel)

In the absence of contraindications, this is usually the DOC for treating mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis.

Naproxen (Aleve, Anaprox DS, Naprelan, Naprosyn)

For relief of mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing the activity of the enzyme cyclooxygenase, which results in a decrease of prostaglandin synthesis.

Ketoprofen

For relief of mild to moderate pain and inflammation. Administer small dosages initially to patients with a small body size, elderly persons, and those with renal or liver disease. When administering this medication, doses >75 mg do not increase therapeutic effects. Administer high doses with caution, and closely observe patients for response.

Acetaminophen (Tylenol, Aspirin Free Anacin, Feverall, Mapap, Cetafen)

DOC for pain in patients with documented hypersensitivity to aspirin or NSAIDs, in those with upper GI disease, or in those who are taking oral anticoagulants.

Acetaminophen with codeine (Tylenol with codeine, Capital/codeine)

The combination of acetaminophen and codeine is indicated for the treatment of mild to moderate pain.

Hydrocodone and acetaminophen (Lorcet Plus, Vicodin, Norco, Verdrocet, Zamicet)

This agent is indicated for the relief of moderately severe to severe pain.

Oxycodone and acetaminophen (Percocet, Endocet, Primlev, Xartemis XR)

The combination of oxycodone and acetaminophen is used for the relief of moderate to severe pain. It is the DOC for aspirin-hypersensitive patients.

Oxycodone/aspirin

This drug combination of oxycodone and aspirin is indicated for the relief of moderately severe to severe pain.

Indomethacin (Indocin,Tivorbex)

Indomethacin is thought to be the most effective NSAID for the treatment of AS, although no scientific evidence supports this claim. It is used for relief of mild to moderate pain; it inhibits inflammatory reactions and pain by decreasing the activity of COX, which results in a decrease of prostaglandin synthesis.