Shoulder Impingement

Shoulder impingement is one of the more common causes of shoulder pain. Impingement is caused by the rubbing of the rotator cuff tendons against the acromion (a bony protrusion of the shoulder blade that extends above the rotator cuff tendons). Certain conditions can cause the space between the acromion and rotator cuff tendons to become smaller and increase the chance of compressing or irritating the rotator cuff. This can be caused by bony “spurs” that may form on the acromion or humeral head. This process causes inflammation, and the tendons can thicken. Fluid-filled sacs, called bursae, within this space also become inflamed. The combination results in pinching of the tendon and bursae between the bones of the shoulder and can produce pain and shoulder dysfunction. The rotator cuff sits directly below the bursa and can also become inflamed and irritated in a condition called rotator cuff tendinitis. In some cases, where this process continues for long periods of time, it can lead to abrasion and tearing of the rotator cuff.

Risk Factors & Symptoms

Risk factors for developing shoulder impingement include repetitive lifting and overhead movements such as throwing, weight training, daily chores, and manual labor. The most common symptom of shoulder impingement is shoulder pain, particularly with overhead activities. Shoulder impingement is diagnosed using physical examination and imaging studies to confirm the diagnosis. The physical examination is used to identify areas of pain, weakness, and changes in range of motion of the shoulder. X-rays help evaluate for the presence of a bone spur or any arthritic changes of the shoulder joint. MRI (magnetic resonance imaging) allows us to evaluate the soft tissue and non-bony parts of your shoulder and specifically look at the bursa and rotator cuff tendons.

Treatment

Treatment of shoulder impingement can be done with non-surgical or surgical means. The goal of treatment is to reduce pain and regain function of the shoulder. Non-surgical treatment is used for patients as a first-line treatment. These therapies are used to reduce inflammation associated with injury and allow you to strengthen the rotator cuff muscles and regain function. Non-surgical treatment options include:

• Rest

• Change in activities: Avoiding activities that irritate the shoulder, specifically overhead motions

• Non-steroidal anti-inflammatory medications (NSAIDs) can help decrease inflammation

• Injections: Steroid injections can help decrease inflammation in the bursa surrounding the rotator cuff tendons, but should be used sparingly. Steroid injections can be used if rest, activity modification, and NSAIDs do not improve the symptoms. There is currently little evidence supporting the use of biologicinjections for shoulder impingement, but this is an area of increased scientific study.

• Physical therapy: This is an important tool to help you strengthen and retrain the muscles of the rotator cuff to work better together

Surgery may be an effective treatment for a small subset of patients who do not respond appropriately to conservative care. Surgical treatments can include:

• Arthroscopic subacromial decompression is performed through the use of specialized camera and small instruments through a series of small incisions in the skin around your shoulder. The chronically thickened and irritated subacromial bursa is removed with a shaving device. If a bone spur is present on the undersurface of the acromion it will be removed as well. The goal is to remove painful bursa and create more room for the rotator cuff to move below the acromion during shoulder motion.

Physical therapy after surgery is critical to your recovery. Surgery removes the structural causes of the problem, but does not restore the strength and coordination of the muscles and tendons that provide stability and function to the shoulder. Adherence to a structured physical therapy program after surgery is essential.