Description

An AC sprain is a stretching of the ligaments that join the clavicle (aka-collarbone) to the scapula (aka – shoulder blade). Research has identified several classifications of injury, but sprains are typically graded 1-5. If the damage to the ligaments is severe enough, the bones no longer touch each other. This is known as a Grade 5 AC sprain, also known as an AC separation.

What are the causes?

AC sprains only occur because of trauma, either in sports or falls with a direct force to the side of the shoulder. The mechanism of injury is similar to the cause of clavicle fractures.

What are the symptoms?

AC sprains cause pain specifically at the AC joint. Depending on the severity of the sprain, the collarbone may appear to be elevated compared to the shoulder blade. Patients will have pain with most motions of the shoulder, particularly moving the arm across the body.

How is it diagnosed?

Your surgeon will perform a thorough history and physical exam including X-rays. The exam will test the laxity at the AC joint. The surrounding structures of the shoulder will be examined to determine if there are other injuries, as rotator cuff tears and clavicle fractures can also occur during trauma. X-rays may or may not demonstrate looseness around the AC joint and are the basis for most classification systems. Clavicle fractures may also be seen on x-ray. MRI may be helpful if your surgeon suspects damage to the rotator cuff.