A bursa is a thin sac toward the top of the shoulder that sits atop the rotator cuff. This thin sac provides a lubrication that allows the tendons to smoothly glide under the bone above them when the arm is raised. Sometimes this bursa can become inflamed, causing shoulder pain with simple movements.
Subacromial bursitis, or inflammation of the bursa below the acromion, may be caused by a bone spur on the undersurface of the bone. This bone spur can pinch the bursa and underlying rotator cuff when the arm is raised out to the side. There are several great treatment options available that can help alleviate the inflammation in the bursa and restore function. When patients fail more conservative treatments, such as physical therapy, anti-inflammatory pain medication, and steroid injections into the bursa, they may be a candidate for a shoulder arthroscopy, removal of the acromial bone spur, and bursectomy, which is removal of the inflamed bursal tissue.
- Persistent shoulder pain when reaching out to the side, behind the back, or across the body
- Limited range of motion
- Pain is usually minimal at rest
- Weakness due to pain
- Physical Therapy - A formal course of physical therapy (PT) is the first line of treatment. PT can help patients regain their strength and range of motion as well as restore the mechanics to the affected joint.
- Injections - Injection of a steroid into the subacromial bursa is a very effective way to reduce the inflammation and pain. It can provide results within one day. It is not recommended to have more than a couple of injections into the bursa because repeat steroid injections around the rotator cuff can weaken the tendon and potentially lead to rotator cuff tears.
- Anti-inflammatories - Nonsteroidal anti-inflammatory medications such as Ibuprofen or Aleve can help decrease inflammation and pain in the subacromial bursa. This can be beneficial in addition to physical therapy, so patients can have less pain while regaining their motion and strength. Prescription-strength anti-inflammatory medications are occasionally prescribed if over-the-counter medications are not working.
- Surgery - If more conservative treatments fail to alleviate symptoms and help patients regain their function, surgery is usually recommended.
Subacromial bursitis can be diagnosed clinically with a detailed history and a thorough physical exam. If patients demonstrate weakness, an MRI will be ordered to ensure no other soft tissue structures have been injured. An MRI evaluates soft tissue structures such as the rotator cuff tendons and subacromial bursa.
Typically, subacromial bursitis is managed conservatively for a few months. Most patients improve without needing surgery. If patients continue to have pain and limitations despite physical therapy, steroid injection, and anti-inflammatories, surgery is recommended.
The most common risks are stiffness, persistent pain, and weakness. Patients with subacromial bursitis commonly use their injured arm less, which can lead to weakness in the shoulder as well as increased tension in the muscles around the shoulder that compensate for the decreased shoulder movement.