What happens with a frozen shoulder?
No one really understands why some people develop a frozen shoulder. For some reason, the shoulder joint becomes stiff and scarred. The shoulder joint is a ball and socket joint. The ball is the top of the arm bone (the humeral head), and the socket is part of the shoulder blade (the glenoid). Surrounding this ball-and-socket joint is a capsule of tissue that envelops the joint.
Normally, the shoulder joint allows more motion than any other joint in the body. When a patient develops a frozen shoulder, the capsule that surrounds the shoulder joint becomes contracted. The patients form bands of scar tissue called adhesions. The contraction of the capsule and the formation of the adhesions cause the frozen shoulder to become stiff and cause movement to become painful.
A frozen shoulder causes a typical set of symptoms that can be identified by your doctor. The most important finding is restricted movement. Other shoulder conditions can cause difficulty with movement of the shoulder, such as a rotator cuff tear; therefore it is important to have an examiner familiar with this condition for a proper diagnosis.
What are the typical symptoms of frozen shoulder?
- Shoulder pain; usually a dull, aching pain
- Limited movement of the shoulder
- Difficulty with activities such as brushing hair, putting on shirts/bras
- Pain when trying to sleep on the affected shoulder
What are the stages of frozen shoulder?
- Painful/Freezing Stage
This is the most painful stage of a frozen shoulder. Motion is restricted, but the shoulder is not as stiff as the frozen stage. This painful stage typically lasts 6-12 weeks.
- Frozen Stage
During the frozen stage, the pain usually eases up, but the stiffness worsens. The frozen stage can last 4-6 months.
- Thawing Stage
The thawing stage is gradual, and motion steadily improves over a lengthy period of time. The thawing stage can last more than a year.
What test are needed to diagnose frozen shoulder?
Most often, a frozen shoulder can be diagnosed on examination, and no special tests are needed. An x-ray is usually obtained to ensure the shoulder joint appears normal, and there is not evidence of traumatic injury or arthritic changes to the joint. An MRI is sometimes performed if the diagnosis is in question, but this test is better at looking for other problems, rather than looking for frozen shoulder. If an MRI is done, it is best performed with an injection of contrast fluid into the shoulder joint prior to the MRI. This will help show if the capsule of the shoulder is scarred down, as would be expected in patients with a frozen shoulder.