Acromioclavicular Joint Injection

Excerpt

The acromioclavicular (AC) joint is a common pain generator in patients presenting with shoulder pain. The incidence of AC joint pain is reported to be roughly 0.5 per 1000/year in primary care. Pain in the AC joint can be traumatic or non-traumatic. Traumatic AC joint pain is typically the result of a direct blow to the superior or lateral aspect of the shoulder. The impact results in a partial or complete tear of the ligamentous structures within the joint, more commonly known as a separated shoulder, and frequently occurs in contact sports such as football and hockey. Patients with separated shoulder often present with a notable deformity over their superior shoulder and pain directly over the AC joint. Traumatic AC joint pain is treated either conservatively with a sling and relative rest or with surgery if the injury is high-grade or severe.

Patients with non-traumatic AC joint pain are usually older than 40 years of age and will typically present with focal shoulder pain located over the superior aspect of the shoulder. The pain is usually insidious and made worse with cross-body adduction of the shoulder. Patients may also describe a grinding sensation in their shoulder. On physical exam, patients will typically have tenderness directly over the AC joint. Bringing the patient’s affected arm into adduction by having them reach across their body often reproduces the pain.

The most common non-traumatic causes of pain in the AC joint are overuse, degenerative changes, and distal clavicle osteolysis. Conservative management, including physical therapy, activity modification, and NSAIDs, are the first line of treatment.

In patients with chronic AC joint pain refractory to initial management, AC joint injections can be both diagnostic and therapeutic, resulting in significant relief. Providers must remain up to date on the indications, possible complications, and most effective methods of performing this procedure to benefit patients suffering from this condition maximally. This article reviews acromioclavicular (AC) joint injections and highlights the role of the healthcare team in performing this procedure.