AC joint separation is damage affecting the ligament that supports the acromioclavicular joint in place at the upper part of the shoulder. The injury is usually caused by a fall onto an extended arm.
The acromioclavicular joint is comprised of the exterior end of the clavicle and the acromion process of the shoulder blade. The 2 bones involved in AC joint separation are linked by the AC ligament. The usual way the AC joint is damaged is resting on the shoulder, elbow or onto an extended hand. In most cases, when an individual fall, the hands are stretched out to break the fall. The force of impact is transmitted up to the wrist and arm up to the shoulder joint.
What are the indications?
- Pain at the end of the clavicle on top of the shoulder
- Radiating pain throughout the shoulder but later localizes to a bony point at the top part of the shoulder
- Pain is aggravated when attempting to move the arm overhead
- Swelling
- Deformity might be seen depending on the severity of the injury such as a lump on top of the shoulder joint
It is important to note that AC joint separation is categorized as grade 1-6 with grade 1 as mild with minimal damage to the ligament and no bone separation while grade 6 is a significant injury with full rupture of the ligament and evident deformity.
Management
The immediate first aid care for AC joint separation is the PRICE method (protection, rest, ice, compression, elevation). You should apply an ice pack along with a compression wrap right away to minimize the pain and swelling. A sling should be worn to immobilize the shoulder as well as relieve the discomfort by taking the weight off the affected arm.
Anti-inflammatory medications such as ibuprofen can be given to minimize the inflammation and pain. If a severe case of AC joint separation is not properly treated, it can lead to lasting deformity that manifests as a lump on the top part of the shoulder. In some cases, ultrasound can be done for minimal injuries or TENS to provide relief from pain for severe cases.
Quick Note / Disclaimer
The material posted on this page on AC joint separation is for learning and educational purposes only. To learn to recognize and manage joint injuries, register for a first aid and CPR course with Ottawa First Aid.