Shoulder and Elbow cases Sternoclavicular (SC) joint dislocations

A patient is brought to the emergency room trauma bay after a motor vehicle collision. During the initial trauma evaluation, a deformity and swelling is noted over the medial aspect of the right clavicle. She has noticeable venous congestion over her right neck and is complaining of numbness and tingling in the right, upper extremity. She is unable to move her right arm because of severe pain and is supporting it across her trunk with her left arm.

Based on the information provided, what is the most likely diagnosis?

1. Bilateral sternoclavicular dislocation

2. Right posterior sternoclavicular joint dislocation

3. Right anterior sternoclavicular dislocation

4. Right acromioclavicular dislocation

5. Right pneumothorax

 

Discussion

The correct answer is (B). Sternoclavicular (SC) joint dislocations are rare and posterior dislocations are much less common than anterior. The patient will be in severe pain that is increased with any movement, particularly when the shoulders are pressed together by a lateral force or placed in a supine position. The injured arm will usually be supported by the uninjured arm. The head may be tilted toward the side of the dislocation. With an anterior dislocation of the SC joint, the medial end of the clavicle might be visibly prominent and palpable anteriorly to the sternum (Fig. 2–69).

 

 

 

Figure 2–69

 

The corner of the sternum might be easily palpated in a posterior dislocation. Swelling may obscure the ability to distinguish an anterior and posterior SC joint dislocation. Bilateral dislocations are extremely rare. Because of this patient’s symptoms of venous congestion with numbness and tingling, it is likely she suffered a posterior SC joint dislocation. A right acromioclavicular dislocation would present with pain and deformity over the lateral aspect of the clavicle. A pneumothorax is a complication of a posterior SC joint dislocation.

A PA view of the chest is the only radiograph available. What additional view would be most beneficial?

1. Lateral view of the chest

2. Swimmer’s view

3. Stryker notch view

4. Serendipity view

 

Discussion

The correct answer is (D). A serendipity view is a 40-degree cephalic-tilt view (Fig. 2–70). This provides a true caudocephalic view of both the SC joint and the medial clavicles. The serendipity view is usually the front line radiograph obtained, however, computed tomography (CT) is the best technique to study the SC joint. Other radiographic views of the SC joint include the Heinig view and the Hobbs view. The lateral view of the chest cannot be used to interpret SC joint dislocations because of the overlap of the medial clavicles with the first rib and the sternum. A swimmer’s view is used for increased visualization of the subaxial cervical spine. The stryker notch view is used for evaluating Hill-Sachs lesions of the humeral

head after glenohumeral dislocations.

 

 

 

Figure 2–70

 

What is the most common cause of a posterior sternoclavicular joint dislocation?

1. Athletic injury

2. Fall from excessive height onto outstretched arm

3. Industrial accident

4. Motor vehicle accident (MVA)

5. Atraumatic instability

 

Discussion

The correct answer is (D). MVA accounts for 40% of SC joint dislocations. Athletic injuries account for 21%. The remaining 39% include falls and industrial accidents. Instability of the SC joint can be classified according to different factors. It can be traumatic or atraumatic; structural or nonstructural; acute, recurrent, or persistent. Causes of atraumatic, structural instability of the SC joint include: Ehlers Danlos syndrome, abnormal clavicular shape, degenerative osteoarthritis, inflammatory arthritis, infection, or sternoclavicular hyperostosis syndrome. Answer E is incorrect because atraumatic instability is not the most common cause of posterior dislocations. SC joint dislocations can occur from direct or indirect force. Direct force only results in posterior dislocation and is when a force is applied directly to the anteromedial aspect of the clavicle. Indirect is when a compressive force is applied to the anterolateral or posterolateral aspect of the shoulder, resulting in an anterior or posterior dislocation, respectively. Most SC joint dislocations are caused by indirect force.

A CT scan of the chest is obtained and shown in Figure 2–71. What is the next best step in managing this patient?

1. Attempting a closed reduction after assuring that a thoracic or cardiothoracic surgeon is available if complications occur

2. Open reduction with assistance from a thoracic surgeon

3. MRI to assess for soft tissue and neurovascular injuries in the mediastinum

4. Conservative management with a figure-of-eight sling

 

 

 

Figure 2–71

 

Discussion

The correct answer is (A). Both anterior and posterior SC joint dislocations that are diagnosed within 7 to 10 days of injury should be initially treated with closed reduction. The caveat is that with posterior dislocations in which there is suspicion of mediastinal involvement, a surgeon with more mediastinal expertise should be consulted. Note that anterior SC joint dislocations are inherently more unstable after closed reduction than posterior dislocations. Open reduction should only be attempted after closed reduction attempts have failed. MRI is not necessary at this point in the case. A CT scan is the preferred imaging modality in the acute setting. A figure-of-eight sling can be used after reduction to promote healing.

Which of the following basic surgical techniques is the most commonly performed for an unreduced SC joint after closed reduction has been attempted?

1. Plate and screw fixation

2. Kirschner wires

3. Steinmann pins

4. Cannulated screw fixation

5. Resecting the medial clavicle

 

Discussion

The correct answer is (E). Adults over the age of 23 should undergo open reduction if closed reduction has failed. If the costoclavicular ligament is intact after reduction, the clavicle medial to the ligaments should be excised. If the ligaments are disrupted, the clavicle must be stabilized to the first rib. Answers A and D are incorrect because these techniques have very limited reports of use and require hardware removal. Answers B and C are essentially contraindicated because of reported incidences of migration and serious complications, including death. If the patient is younger than 23 years old, they can likely be treated nonoperatively because the remodeling provided by the open physes will eliminate most of the bone deformity or displacement. The clavicle is the first bone to ossify (at 5 weeks of gestation), but the medial epiphysis is the last to fuse (at 23–25 years).

 

Objectives: Did you learn...?

 

Understand that SC joint injuries are rare?

 

Recognize the different mechanism of anterior and posterior SC joint dislocations?

 

Describe the most appropriate radiographic view for SC joint pathology?

 

Understand the different treatment options for anterior and posterior SC joint dislocations?

 

Understand the important complications that can be associated with posterior SC joint dislocations and the importance for a multi-disciplinary approach when indicated?