What is a sternoclavicular dislocation?
The sternoclavicular joint can dislocate from its normal position. The clavicle will either dislocate in front (an anterior SC dislocation) or behind (a posterior SC dislocation). The posterior SC dislocations are more worrisome because of the important structures that are just behind the sternum.
How does a sternoclavicular joint dislocation occur?
Dislocations of the SC joint are usually the result of an injury to the shoulder. Most commonly, the outside/front of the shoulder is struck forcefully, and an anterior SC dislocation occurs. In some cases, a blunt force directly to the front of the chest can cause a posterior SC dislocation.
How is a sternoclavicular joint dislocation diagnosed?
A SC injury can be difficult to see on a regular x-ray. A special projection, called a 'serendipity view' x-ray can help show the SC joint and if it is injured. If the SC joint appears to be injured, a CT scan (CAT scan) is often performed to better evaluate the type of dislocation.
Symptoms of a SC dislocation depend on whether or not it is an anterior or posterior dislocation. In the case of an anterior SC dislocation, you can usually see the dislocated end of the clavicle. Patients have pain and swelling in this area.
Patients with a posterior SC joint dislocation may have a subtle dimpling of the skin over the SC joint, as well as pain and swelling. In addition, patients can have difficulty breathing, painful swallowing, and abnormal pulses caused by compression of the trachea, esophagus, and blood vessels.
What is the treatment of a sternoclavicular joint dislocation?
Simple sprains to the SC joint are treated symptomatically with a sling and anti-inflammatory medications. In the acute setting, a reduction (relocation) of the SC joint can be attempted by sedating the patient and pulling gently on the arm. This may allow the SC joint to 'pop' back into position. The SC joint does not necessarily need to be relocated to have a good long-term result.
Is surgery ever necessary for a SC dislocation?
Surgery to relocate the SC joint is considered for posterior SC dislocations, and some painful, symptomatic anterior SC dislocations. If closed reduction is not successful, then surgery may be done to relocate the SC joint and repair the damaged SC joint capsule.
When surgery is performed for a posterior SC dislocation, the procedure is done with both an orthopedic and a vascular surgeon available. The reason is that there is a chance of damage to the major blood vessels of the chest, and a vascular surgeon must be immediately available if needed.
What else can mimic symptoms of a SC dislocation?
In any patient younger than 25 years old, a growth plate fracture of the clavicle should be suspected, rather than a SC joint dislocation. The medial clavicular growth plate is the last growth plate to close in the body. It is this growth plate that is injured, rather that the SC joint, in most patients under the age of 25. The treatment is similar, except that it is very rare for these young patients to require surgery.
Last updated: 03/14/2006
References:
- Medvecky MJ, Zuckerman JD. "Sternoclavicular joint injuries and disorders" Instr Course Lect. 2000;49:397-406.
