The acromio-clavicular (AC) joint is the joint formed between the clavicle (collarbone) and the acromion (the tip of the shoulder blade). The AC joint is a link between the arm and the trunk and is the only bony join between the shoulder blade and the rest of the body. It helps transmit load from the arm to the trunk in pushing, pulling punching and resting on the arm.AC Joint is usually injured by a fall directly onto the shoulder or a fall onto the arm or a tackle.

• Type I - joint sprained without tear of either ligament.
• Type II - AC ligaments torn but CC ligaments intact. Lateral end of clavicle not elevated.
• Type III - AC and CC ligaments torn, >5 mm elevation of AC joint in unstressed X-ray. Take care to distinguish from type III (distal) clavicular fracture.
• Type IV - lateral clavicle separated and impaled posteriorly into trapezial fascia.
• Type V - complete separation of clavicle and scapula with gross upward clavicular displacement.
• Type VI - as type V but with clavicle detached inferiorly and displaced behind tendons of biceps and brachioradialis.

• Rest
• Ice
• Compression
• Support (a sling may be worn)
• Anti-inflammatory medications or pain re-lief medication should be given.

• Immobilize the shoulder in a sling or other device for several weeks following treatment. Plenty of rest is needed. The sore area can be iced 3 to 4 times a day
• Non-steroidal anti-inflammatory medication- Drugs like aspirin and ibuprofen reduce pain and swelling.
• When the pain and swelling go down. Then physiotherapy is started.

• Movement within the pain free range will help in maintaining mobility of the surrounding structures.
• Taping may be beneficial to support the position of the joint.
• Modalities are given for pain relief.
• Load bearing exercises can be added to restore the normal function of the joint and surrounding muscles.
• Mobility exercises may be incorporated to ensure normal function is achieved.

In severe cases where the clavicle is completely torn away from the ac-romion the joint may remain painful and unstable and require surgical fixation.