Cite This Article

Zhou R, Ko J, Tomesch, A. The Forgotten Joint. Ortho Pearls. June 12, 2024; Available: https://www.orthoempearls.com/articles/the-forgotten-joint

What structures does the physical exam suggest are affected? What is your suspected diagnosis?

Sternoclavicular (SC) joint and clavicle. There is widening of the right sternoclavicular joint suggesting possible SC joint dislocation.

The superior-lateral sternum (manubrium) articulates with the medial clavicle to form the sternoclavicular joint, joining the upper limb with the axial skeleton (Image 2) [1,2].

Image 2.  Case courtesy of Craig Hacking, Radiopaedia.org, rID: 84425

In the setting of blunt trauma to the shoulder, palpable deformity of the medial clavicle is suggestive of sternoclavicular joint dislocation with anterior displacement of the clavicle [3].

What is the next step in management?

X-ray +/- CT scan of the chest. Prominence of the medial clavicle after blunt trauma to the shoulder should prompt radiographic imaging to assess for anterior SC joint dislocation and to rule out clavicle fracture.

• Pearl: Specialized (lordotic/serendipity) chest X-ray views can help visualize the SC joint and reduce superimposed structures [4], though CT is usually required to confirm the diagnosis and is the preferred imaging modality of choice [5].

What findings would be expected on confirmatory testing?

Anterior displacement, lateral displacement, and elevation of the clavicle.

• Pearl: Lateral displacement and elevation of the affected clavicle are also expected in anterior SC joint dislocation, best demonstrated by CT scan (Image 2) [6]. Depression of the affected clavicle is expected with posterior SC joint dislocation.

Image 3. Case courtesy of Craig Hacking, Radiopaedia.org, rID: 92310

What life-threatening pathology should be considered with this type of injury?

If there is a posterior sternoclavicular joint dislocation, there needs to be a higher concern for internal chest injuries. Posterior displacement of the clavicle can compromise the lung apices, trachea, great vessels, and other mediastinal structures. As a result, 30% of posterior SC joint dislocations are associated with devastating complications, including pneumothorax, vascular injury, and acute limb ischemia [7,8].

• Pearl: Posterior SC joint dislocation is a life-threatening orthopedic injury often requiring emergent surgical decompression and joint reduction. Often these require a CT angiogram to assess for any vascular injury and/or need for surgical consultation. 

Does orthopedic surgery need to be consulted?

If there is an anterior dislocation, orthopedic surgery does not need to be emergently or urgently consulted. These can follow up with orthopedics as an outpatient. However, if there is a posterior dislocation, emergent orthopedic evaluation is recommended. Urgent evaluation could be appropriate if no concerning findings on CT imaging.