A shoulder separation is not truly an injury to the shoulder joint. The injury actually involves the acromioclavicular joint (also called the AC joint). The AC joint is where the collarbone meets the highest point of the shoulder blade (acromion).
The most common cause for a separation of the AC joint is from a fall directly onto the shoulder. Shoulder separation often involves a soft-tissue or ligament injury, but may also include fracture (broken bone). Because shoulder separation actually affects the AC joint, it is sometimes referred to as AC shoulder separation.
What Causes AC Shoulder Separation?
Shoulder separation is caused by sudden trauma to the shoulder, in events such as a fall with an outstretched hand, bicycle or car accidents, or from direct blows as experienced in full-contact sports such as football or hockey.
What Does AC Shoulder Separation Feel Like?
Symptoms of a separated shoulder include:
- Intense pain, radiating to the top of the shoulder
- Tenderness of the AC joint — between the collarbone and shoulder
How is a Separated Shoulder Diagnosed?
A physical examination by a physician will help determine if you have a separated shoulder. The physician may also use x-ray or magnetic resonance imaging (MRI) to assist with diagnosis and to rule out fracture.
There are three common types (grades) of separation injury. The typical sports injuries include:
- Grade I: stretching or slight tearing of the acromioclavicular
- Grade II: complete tearing of the acromioclavicular ligament
- Grade III: complete joint separation involving the tearing of the acromioclavicular ligament and the coracoclavicular ligaments, causing the clavicle to push up so that the damage is visible on the shoulder
There are a total of six grades of severity of AC separations. Grades I-III are the most common. Grades IV-VI are very uncommon and are usually the result of a very high-energy injury such as one that might occur in a motor vehicle accident. Grades IV-VI are all treated surgically because of the severe disruption of all the ligamentous support for the arm and shoulder
How is Shoulder Separation Treated?
The treatment of an AC separation depends on the grade of the injury. The classification helps the physician choose the correct treatment approach. Grades I – III are usually treated non-operatively. The majority of patients will have a period of discomfort. Once this discomfort disappears, the shoulder is usually fully functional.
AC shoulder separation treatments typically include:
- A sling to immobilize the affected arm and prevent further injury
- Ice to decrease inflammation
- Anti-inflammatory medicine
- Resting the AC joint
Depending on the type of AC injury, patients usually heal with rest and non-operative therapy within two to three months. The range, dependent on grade, is usually two weeks for a Type I injury, six weeks for a Type II, and up to 12 weeks for a Type III.
Surgery may be necessary for AC separations that do not respond well to non-operative treatment. If, after 2 to 3 months, pain continues in the AC joint with overhead activity or in contact sports, surgery may be necessary.