Sternoclavicular Joint Dislocation: Serious concern or not a big deal?

Case

A healthy 8-year-old girl was playing basketball and fell forward onto the anterior aspect of her right shoulder. When she rotates her shoulder in a circular motion, she feels a “popping” sensation in the middle of her chest. Her mother further notes a slight deformity near the center of her chest. She reports no other injuries and is not currently in pain.

Exam

Well-developed young female in no acute distress with full range of motion of her right shoulder. There is a palpable deformity at the right sternoclavicular joint without tenderness. A reproducible pop is evident with circumduction of the right shoulder. Neurovascular exam is normal. Skin is intact.

Clinical image showing a protrusion over the right SCJ. Corresponding AP plain film demonstrating widening of the SCJ

Diagnosis

Anterior sternoclavicular joint dislocation

Treatment

Sling for support/comfort, and outpatient orthopedics follow-up.

About Sternoclavicular Joint (SCJ) Dislocations

The SCJ is the only true articulation of the upper extremity with the axial skeleton. It is a well-supported joint with multiple ligamentous attachments to surrounding structures and thick anterior/posterior sternoclavicular ligaments. Note that the joint closely overlies the vascular and airway structures of the mediastinum.

Injuries to the SCJ are rare, comprising less than 1% of all joint dislocations and only 3% of shoulder girdle injuries. The SCJ can be dislocated anteriorly or posteriorly.  A thorough neurovascular examination of the affected extremity is essential given the clavicle’s proximity to the brachial plexus and important vascular structures. SCJ injuries may include physeal fractures in young patients (the physis doesn’t fuse until the early to middle twenties!). CT is typically favored as the imaging modality of choice over plain radiographs.

Mechanism of injury

• Direct - force applied to the medial aspect of the clavicle forces it posteriorly (i.e., MVC or when one athlete falls on top of another)
• Indirect - force applied to the shoulder and is transmitted medially (commonly seen in football pileups or falls on an outstretched arm)

A - A posterior SCJ dislocation caused by a force applied to the posterolateral aspect of the shoulder.

B - An anterior SCJ dislocation caused by a force applied to the anterolateral aspect of the shoulder.

Anterior dislocation

• The more common type of SCJ dislocation.
• Largely a cosmetic defect, with minimal functional impairment in mild to moderate cases.
• Most patients can be treated conservatively with a sling, NSAIDs, and ice. This typically results in a favorable outcome with the joint stabilizing in the subluxed position. Patients can be pain free in as little as 2-3 weeks and have full return to unrestricted activity by 3 months (~80% of patients show no functional impairment).
• Closed reduction can be attempted. However, re-dislocation rates range from 21% - 100%.
• Rarely is operative reduction indicated and, when performed, has mediocre outcomes.

Posterior dislocation – an orthopedic emergency

• Less common than anterior SCJ dislocation.
• 30% of posterior dislocations are associated with life-threatening complications due to mediastinal injury.
• Extent of injury is best characterized by CT angiogram.
• Emergent consultation of orthopedic surgery is recommended.
• Reduction is best performed by orthopedics in the OR with vascular surgery readily available.
• However, in the event of a pulseless limb, consider emergent reduction in the ER.

Axial CT image showing retropulsion of the medial aspect of the left clavicle behind the manubrium with potential compromise of the mediastinal structures. The corresponding anatomical diagram highlights the structures at risk.

The most common reduction technique involves placing towels between the patient’s shoulder blades. Then, traction is applied to the affected arm while holding it in abduction (90 degrees) and extension (15 degrees). An assistant may be required to apply manual pressure to the medial aspect of the clavicle to facilitate reduction of an anterior dislocation. Similarly, an assistant may use a towel clip to percutaneously grasp a posteriorly dislocated clavicle and apply forward traction.

Take Home Points

• Sternoclavicular joint injuries are rare injuries.
• In younger patients be careful to look for physeal fracture and displacement.
• Anterior dislocations can be conservatively managed and have favorable outcomes.
• Posterior dislocations can be life threatening and require emergent orthopedic consultation.

Faculty Reviewer: Jeffrey P. Feden, M.D.

 

References

Morell DJ, Thyagarajan DS. Sternoclavicular joint dislocation and its management: A review of the literature. World J Orthop 2016 April 18; 7(4): 244-250

Jiang W, Gao Sg, Li Ys, Lei Gh. Bipolar dislocation of the clavicle. Indian J Orthop 2012;46:721-4

Roepke, Clare et al. Chest Pain Bounce-Back: Posterior Sternoclavicular Dislocation Annals of Emergency Medicine, Volume 66 , Issue 5 , 559 - 561

Bjoernsen, LP, Ebinger, A. Shoulder and Humerus Injuries. In: Tintinalli’s Emergency Medicine. 8th ed. New York: McGraw-Hill; 2016

Bengtzen, R, Daya, M. Shoulder. In: Rosen's emergency medicine: concepts and clinical practice 9th edition. Philadelphia, PA: Mosby/Elsevier; 2017

Egol, KA, Koval, KJ, Zuckerman, JD. Acromioclavicular and Sternoclavicular Joint injuries. In: Handbook of Fractures. 5th ed. Philadelphia, PA : Wolters Kluver; 2014

Thurston,M, Jones, J, et al. Sternoclavicular joint dislocation [Internet]. [Accessed August 15, 2017]. Available from: https://radiopaedia.org/articles/sternoclavicular-joint-dislocation

Cadogan, M. Sternoclavicular Joint Dislocation [Internet]. 2014. [Accessed on August 15, 2017]. Available from: https://lifeinthefastlane.com/sternoclavicular-joint-dislocation.

Weatherford, B. Sternoclavicular Dislocation [Internet] [Accessed on August 15, 2017]. Available from: http://www.orthobullets.com/trauma/1009/sternoclavicular-dislocation