Peer Reviewed Patient Education

How is an acromioclavicular separation diagnosed?

After evaluating the history of the patient's injury the doctor will examine the shoulder area looking for signs of fracture or dislocation by comparing the overall position of the arm and shoulder to the uninjured side. The AC joint itself is easily examined because it is located right under the skin. The doctor will gently feel the bones and soft tissue around the joint and between the acromion and clavicle. There may be a bump, tenderness or instability, which would suggest a joint separation. Crepitus (noise) as the bones move may indicate a fracture. The doctor also evaluates the patient's range of motion and performs tests to isolate specific areas of pain and weakness.

Further evaluation may include:

• A diagnostic anesthetic injection, which blocks pain, can help confirm the diagnosis.
  
• X-rays can confirm a diagnosis of an AC joint separation and can help the physician determine whether the injury is a separation or a fracture. A new cross body X-ray has been recently developed which is very helpful in confirming the diagnosis and may be in general use in the near future.