Acromioclavicular Injuries of the Shoulder

The AC (acromioclavicular) joint is the joint in the shoulder where the collarbone (clavicle) meets the shoulder blade (scapula). The part of the shoulder blade connected to the collarbone is called the acromion. Common problems with and treatments for the AC joint are detailed below.


Acromioclavicular InjuriesArthritis occurs when the joint has been injured and the smooth padding between the joints (cartilage) is lost. This is the wear and tear seen in most joints of body if they have been overused .This causes the joint to produce pain and swelling which is worse with activity.

Treatment of AC Arthritis

  • There is currently no way to replace the cartilage damaged by arthritis. The best way to improve the condition is to decrease the activities which aggravate the problem. Application of ice to the joint helps decrease pain and soreness (inflammation). The use of non-steroidal anti-inflammatory medication is helpful.
  • If less conservative measures do not work, then cortisone shots (injections) may be used. These are medications given which are very strong anti-inflammatories; they decrease the soreness in the joint and swelling.
  • If non-surgical measures fail, surgery may be recommended. The procedure is generally removal of a portion of the end of the clavicle. This is the part of the collarbone closest to your acromion which is stabilized with ligaments to the acromium of the shoulder blade. This surgery may be performed using a tube-like instrument with a light (arthroscope) for looking into a joint. It may also be performed as an open surgery through a small incision by the surgeon. Most patients will have good range of motion within six weeks and may return to all activity including sports by 8-12 weeks, barring complications.

AC Joint Separation

AC Joint separation means that the ligaments connecting the acromium of the shoulder blade and collarbone have been damaged, and the two bones no longer line up. AC separations can be anywhere from mild to severe, and are “graded” depending upon which ligaments are torn and how badly they are torn.

  • Grade I Injury – the least damage is done, and the AC joint still lines up
  • Grade II Injury – damage to the ligaments which reinforce the AC joint. In a Grade II injury these ligaments are stretched but not entirely torn. When stressed, the AC joint becomes painful and unstable
  • Grade III Injury – AC and secondary ligaments are completely torn, and the collarbone is no longer attached to the shoulder blade. This results in deformity; a prominence of the end of the clavicle

Treatment of AC Separation

The initial treatment is to decrease pain. This is best accomplished by immobilizing the arm in a sling and placing an ice pack to the shoulder for 20 to 30 minutes every two hours as needed. As the pain starts to subside, it is important to begin moving the fingers, wrist, and elbow, and eventually the shoulder in order to prevent a stiff or “frozen” shoulder. Instruction on when and how much to move the shoulder will be provided by your caregiver. The length of time needed to regain full motion and function depends on the amount or grade of the injury. Recovery from a Grade I AC separation usually takes 10 to 14 days, whereas a Grade III may take six to eight weeks.

Grade I and II separations usually do not require surgery. Even Grade III injuries usually allow return to full activity with few restrictions. Treatment is also based on the activity demands of the injured shoulder. For example a high level quarterback with an injured throwing arm will receive more aggressive treatment than someone with a desk job who rarely uses his arm for strenuous activities. In some cases a painful lump may persist which could require a later surgery. Surgery can be very successful, but the benefits must be weighed against the potential risks.

AC Joint Fracture

AC Joint Fracture means that there has been a break in the bones of the AC joint, usually the end of the clavicle.

Treatment of AC Joint Fracture

Fracture treatment depends on the type of fracture. Sometimes a splint or sling may be all that is required. Other times surgery may be required for repair. This is more frequently the case when the ligaments supporting the clavicle are completely torn. Your caregiver will help you with these decisions and together you can decide what will be the best treatment for you.

Home Care Instructions

  • Apply ice to the injury for 15 to 20 minutes each hour while awake for 2 days. Put the ice in a plastic bag and place a towel between the bag of ice and your skin.
  • If a sling has been applied, wear it as instructed. You may remove the sling or splint for bathing or showering or as directed. Be sure to keep your shoulder in the same place as when the sling is on. Do not actively lift your arm.
  • If a figure-of-eight splint has been applied it should be tightened gently by another person every day. Tighten it enough to keep the shoulders held back. Allow enough room to place the index finger between the body and strap. Loosen the splint immediately if you feel numbness or tingling in your hands.
  • Take over-the-counter or prescription medicines for pain, discomfort, or fever as directed by your caregiver.
  • If you have received a follow up appointment, it is very important to keep that appointment in order to avoid long term complications, chronic pain, or disability.

Seek Medical Care If

  • You have pain not relieved with medications
  • There is increased swelling or discoloration that continues to get worse rather than better
  • For any reason you have been unable to follow up as instructed
  • You have progressive numbness and tingling in the arm forearm or hand

Seek Immediate Medical Care If

  • Your arm is numb, cold, or pale
  • You have increasing pain in the hand, forearm or fingers

Make Sure You

  • Understand these instructions
  • Will watch your condition
  • Will get help right away if you are not doing well or get worse

For more information about acromioclavicular injuries of the shoulder, please call (918) 494-AOOK (2665).