The acromioclavicular (AC) joint connects the collarbone (clavicle) to the highest point of the shoulder blade (acromion). Pain originating from the AC joint is a common source of shoulder discomfort, often resulting from sudden trauma or gradual wear and tear. Following a structured recovery plan is central to restoring function. This guide provides a framework for managing AC joint pain, from initial treatment to full recovery.
What Causes AC Joint Pain
The most frequent cause of acute AC joint pain is a direct impact injury, often sustained from a fall onto the shoulder. This trauma can lead to an acromioclavicular joint separation, which is the stretching or tearing of the ligaments supporting the joint. These separations are classified using a grading system that indicates severity and influences the healing timeline.
A Grade I separation involves a minor sprain of the ligaments, typically resolving within two weeks. Grade II injuries involve a more significant tear of the acromioclavicular ligaments, which may require approximately six weeks for recovery without surgery. A Grade III separation involves a complete tear of the primary supporting ligaments, and non-operative recovery can take up to 12 weeks or more.
Chronic pain in this area often stems from osteoarthritis, a degenerative condition where the cartilage within the joint wears down over time. This attrition causes bone-on-bone friction, leading to localized pain and tenderness. Activities that involve reaching across the body or heavy overhead lifting can aggravate the symptoms of AC joint arthritis.
First Steps for Immediate Relief
Managing a new AC joint injury begins with protecting the joint and controlling inflammation. Apply an ice pack to the painful area for 15 to 20 minutes several times a day, particularly in the first 48 to 72 hours following an injury.
Rest is achieved by avoiding activities that cause pain, especially lifting or movements that compress the joint. Immobilization with a sling can help temporarily support the arm and protect the injured ligaments from strain. However, the sling is generally only used for comfort and a short period to prevent excessive stiffness.
Over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, can assist in managing pain and inflammation. These initial steps are designed for acute symptom relief and do not replace a full medical evaluation.
The Path to Full Recovery Through Rehabilitation
Once the acute pain and swelling have subsided, the next phase focuses on regaining functional range of motion and strength. Physical therapy is instrumental in this process, beginning with gentle movements that do not stress the AC joint directly. Early-stage exercises often include pendulum swings, which use gravity to facilitate passive arm movement and improve circulation.
As comfort improves, the focus shifts to active-assisted range of motion exercises, such as using the unaffected arm or a stick to guide the injured arm through movements. This helps prevent the shoulder from stiffening without putting excessive strain on the healing ligaments. The next progression involves strengthening the muscles that stabilize the shoulder blade (scapula).
Scapular stabilization exercises, such as squeezes or retractions, help create a stable base for the shoulder. Strengthening the rotator cuff muscles (e.g., internal and external rotation with a light resistance band) is important for long-term joint support. Consistency is necessary, as full recovery for moderate separations can take several weeks to months to achieve full strength and function.
Advanced Medical Treatment Options
When conservative measures fail to alleviate persistent pain, or if the injury is severe, advanced medical interventions may be considered. For chronic pain related to AC joint osteoarthritis or persistent inflammation, a healthcare provider may recommend a corticosteroid injection. This procedure delivers a potent anti-inflammatory medication directly into the joint space to reduce swelling and provide pain relief.
Diagnostic imaging, such as X-rays or magnetic resonance imaging (MRI), helps confirm the diagnosis and assess the extent of ligament or cartilage damage. Surgery is typically reserved for high-grade separations, usually Grade III or higher, or in cases where non-operative treatment has not succeeded after several months of dedicated effort.
Surgical goals include stabilizing the joint by reconstructing torn ligaments or removing the damaged end of the collarbone (Distal Clavicle Excision, or DCE). The DCE procedure creates a small gap between the collarbone and the acromion, eliminating painful bone-on-bone contact associated with chronic arthritis. Recovery is followed by a structured physical therapy program that guides the patient back to full activity.