Bursitis of the ShoulderBursitis of the shoulder (impingement syndrome) occurs when there is inflammation (swelling and redness) between the top of the arm bone (humerus) and the tip of the shoulder (acromion). Between these bones lie the tendons of the rotator cuff and a fluid-filled sac (the bursa) that protects the tendons. Normally, the tendons slide effortlessly within this space. In some people, this space becomes too narrow for normal motion. This causes irritation to the tendons and bursa, which become inflamed. Inflammation causes the tendons and bursa to swell, making the space for movement still smaller. Eventually, this space becomes too narrow for the tendons and the bursa. Every time they move, they are pinched between the bones. This is the impingement.
Often there is an initial injury that sets off the process of inflammation. After that, the problem can spiral into a worse condition. Once there is an initial injury, the tendons and bursa become inflamed. This inflammation causes a thickening of these structures. The thickening then takes up more space, pinching on the tendons and bursa even more. This causes more inflammation, and more thickening of the tendons and bursa, and so on.
Causes and Risk Factors
In many people with this problem, the shape of the bones is such that they have less space than most other people. Even small thickenings of the tendons or bursa can cause symptoms.
Reducing the inflammation is the first step in treating shoulder bursitis. Avoid doing the things that cause pain, such as reaching or stretching beyond your comfort zone. Inflammation can also be treated with anti-inflammatory medications such as Motrin or Advil, among many others. These drugs help reduce the swelling and pain.
For many patients, a few weeks of these measures will be enough to treat shoulder bursitis. After the pain is gone, simple exercises or physical therapy may help you return to normal, pain-free activities.
If the symptoms don't go away, the next step is usually a cortisone injection, or steroid shot, into the swollen area. Cortisone is a powerful drug that treats swelling, not pain. If your initial symptoms are significant, your doctor may give you a cortisone injection on your first visit. The most significant downside is that cortisone injections may weaken tendons. Repeated cortisone injections should be considered with care.
Surgery is sometimes needed to treat shoulder bursitis. The surgical procedure is called a subacromial decompression. This can be done using a small incision with a special, minimally invasive probe called an arthroscope (arthroscopic subacrominal decompression). During the surgery, the inflamed bursa, some of the bone and any spurs are removed to create a larger space for the rotator cuff tendons. The doctors at the Cedars-Sinai Orthopaedic Center can discuss whether this is an option for you.