A shoulder separation is an injury to the ligaments that connect the clavicle (collarbone) to the highest part of the scapula (shoulder blade), the acromion. The connection of these two bones is known as the acromioclavicular joint hence a shoulder separation can also be called an acromioclavicular separation or an AC separation.
Ligaments are strong bands of connective tissue that attach bones to bones, helping to stabilize joints. There are several ligaments attaching the clavicle to the scapula, both around the AC joint and also further along the clavicle. A severe injury to the shoulder can cause the ligament to tear, partly or completely, which can result in the two bones separating. Sometimes the injury includes a broken bone.
The most likely causes of a shoulder separation are a fall onto the shoulder or a heavy blow to the top of the shoulder that forces the clavicle downwards and away from the scapula. This might typically happen in a sporting injury or a vehicle accident.
- Depending on the severity of the injury, there may be a visible deformity on the top of the shoulder. The end of the clavicle, having been separated from the acromion, would form a lump under the skin.
- Pain is usually present, with the desire to support the affected arm with the other hand.
- Tenderness at the acromioclavicular joint site.
- Possible swelling or bruising on the top of the shoulder.
- Numbness or muscle weakness in the affected arm.
- Decrease in mobility of the shoulder.
It is possible that a severe injury may only produce relatively mild symptoms, so it is important to seek medical advice if you suspect you may have a shoulder separation.
Your doctor will ask about your medical history, particularly any previous injuries to your shoulder. You will also be asked about your general lifestyle and activities. Your shoulder will be physically examined, and X-rays will be taken in order to assess the condition of the acromioclavicular joint. Other diagnostic scans, such as MRI or ultrasound, that show the soft tissues in more detail than X-rays, may be performed at a later date.
Treatment will depend on the grade of injury that is diagnosed. Types I and II shoulder separations usually respond to conservative (non-surgical) treatment. Type III injuries are a little more complicated in terms of which treatment is best; people whose occupations require heavy labor or overhead movements may be more appropriate candidates for surgery. Types IV, V, and VI are less common and may include damage to associated muscles. Surgery is the likely treatment for these injuries.
Immobilize the joint by placing the shoulder in a sling or shoulder brace. This is to prevent further damage to the joint caused by the weight of the arm pulling on the joint, and also to restrict movement. Once the acute stage of the injury is over, usually after a few days, it is helpful to begin moving the shoulder gently to minimize stiffness and decrease the risk of developing a frozen shoulder (adhesive capsulitis).
Apply ice, crushed in a bag and wrapped in a towel, to the top of the shoulder. You can apply ice for as long as is comfortable, several times a day. It will reduce swelling and help to relieve pain.
Over-the-counter NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen (Advil), naproxen (Aleve), or aspirin can be taken to help reduce swelling, or acetaminophen (Tylenol) for pain relief.
Physical therapy to rehabilitate the joint will probably begin after a few days, when the initial swelling and pain has diminished. Your doctor or physical therapist will design a program specifically for you, based on your particular injury.
Some of the most severe shoulder separations require surgical repair, as might injuries that fail to respond to conservative treatment, and deformities of the shoulder that cause irritation. Surgery to reattach ligaments can be very successful even if performed some time after the injury, so in many instances it is sensible to wait to see if other treatments resolve the problem. Surgery might also be performed to trim the end of the clavicle so that it no longer rubs against the acromion.
Most people recover well from a shoulder separation and can return to normal activities within two to three months. Sometimes a deformity remains, but does not affect shoulder mobility. If pain persists, it is usually due to the ends of the bones in the acromioclavicular joint continuing to rub against each other, or the development of arthritis, or the joint cartilage between the bones has been injured.
When your doctor advises that it is safe to do so, you may begin some gentle rehabilitation exercises. These should be done on a daily basis to gradually increase the range of motion of your shoulder. Strengthening exercises will begin once you have been performing range of motion exercises for a few days. You will be prescribed specific exercises, but you can begin with the following:
Bend forward at the waist and allow your injured arm to hang straight down towards the floor. Gently move your hand in small circles, both clockwise and anticlockwise. The momentum will cause your arm to move.
Standing, hold a stick in both hands with your palms facing down. Slowly, keeping your elbows straight, lift your arms above your head. Hold the stretch for 5 seconds then lower your arms. Repeat 10 times.
Standing, hold a stick behind your back, using both hands. Slowly lift the stick away from your back. Hold the stretch for 5 seconds then lower. Repeat 10 times.
Stand with your arms at your sides; keeping your elbows straight, carefully raise your arms out to the side and as high as they will go without pain. Hold for 5 seconds. Repeat 10 times.
Scapular range of motion:
Standing, shrug your shoulders up. Hold for 5 seconds. Squeeze your shoulder blades back towards each other. Hold for 5 seconds. Drop your shoulder blades down as though putting them in a back pocket. Hold for 5 seconds. Repeat exercise 10 times.