Frozen shoulder syndrome, known medically as adhesive capsulitis, is a condition when the range of motion in the shoulder joint is so limited that it feels almost as if the shoulder is frozen in place. At the extreme end of this condition, patients are unable to move their shoulder at all. There may be shoulder pain as a result, and normal, daily activities may become impossible or painful to complete. Following a shoulder injury, care should be taken to help prevent the development of frozen shoulder syndrome. Here’s what you need to know.

What causes frozen shoulder syndrome?

The shoulder joint is a ball-and-socket joint that allows a full range of motion up and down and in a large circle. The head of the humerus – the upper arm bone – is the ball that fits into the shallow socket of the shoulder blade. Connective tissue called the shoulder capsule surrounds the entire joint, and movement is lubricated by synovial fluid.

Frozen shoulder syndrome has a variety of causes. If a person stops using their shoulder due to pain or injury, the shoulder will naturally become stiff from disuse. Chronic health conditions such as diabetes or stroke may also cause someone to stop using their shoulder.

Once the joint begins to stiffen (or as a normal response to injury), scar tissue may begin to develop in the shoulder capsule, effectively “freezing” the shoulder in place. The shoulder capsule comes inflamed and extremely painful to move.

Frozen shoulder syndrome occurs over a long period of time as movement in that joint slows or stops and scar tissue builds.

Symptoms of frozen shoulder syndrome

There are three stages to frozen shoulder syndrome, each of which has its own symptoms.

Stage 1: Freezing

As this stage begins, patients may experience increasing pain in their shoulder accompanied by decreasing range of motion. In response to the increased pain, patients may stop moving their shoulder as much, which only exacerbates the condition. This stage can last anywhere from six weeks to nine months.

Stage 2: Frozen

During this stage, patients may not experience much pain, but movement may become impossible. Range of motion is greatly diminished or disappears completely, even to lift the arm up a few inches. Daily life becomes challenging during the four weeks to six months of this stage.

Stage 3: Thawing

This recovery period of frozen shoulder syndrome can last anywhere from six months to two years, depending on the severity and amount of scar tissue built up. Shoulder range of motion is gradually restored to normal. Pain decreases substantially or is eliminated entirely once inflammation is under control.

The length of each stage depends greatly on treatment. For patients who do not see a doctor or begin treatment, frozen shoulder can persist far beyond what is necessary.

In some patients, pain may seem to increase during sleep. This may be an actual increase, or it may be due to the lack of other distractions. Frozen shoulder syndrome does not often reoccur in the same shoulder.

Diagnosing frozen shoulder syndrome

A thorough medical exam is the first step in the diagnosis of frozen shoulder syndrome. This includes medical history that focuses on previous injuries to the area or family history of any medical conditions that might place a patient at risk for frozen shoulder syndrome.

Doctors may utilize X-rays to look for damage to the dense structures of the shoulder (bones). They may also be able to identify solid masses or any previously undetected injury.

Magnetic resonance imaging (MRI) or ultrasound are two other ways in which doctors can identify inflammation and scar tissue in the shoulder capsule. This inflammation and scar tissue, when combined with pain and decreased range of motion, can help diagnose frozen shoulder syndrome.

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