A frozen shoulder is a common cause of shoulder pain and discomfort. In fact, a frozen shoulder is the second most common cause of shoulder pain (right behind rotator cuff tendonitis/bursitis), but the condition may be harder to diagnose. Many people who have a frozen shoulder are incorrectly diagnosed as having bursitis. It’s safe to say that frozen shoulder is the most commonly misdiagnosed problem of the shoulder joint.
Differentiating between bursitis and frozen shoulder can be confusing, but with an appropriate examination your doctor should be able to distinguish these conditions. Interestingly, special tests or interventions are generally not necessary, and the best way to differentiate these conditions is with a careful physical examination.
Signs of Frozen Shoulder
- Shoulder Pain
Typical pain of a frozen shoulder is described as a dull, aching pain. Often the discomfort surrounds the front, back, and side of the shoulder. At times the pain will extend down the upper part of the arm. Usually the pain is manageable with the arm held at your side, but even small movements may cause significant discomfort.
- Limited Range of Motion
The hallmark finding of patients with a frozen shoulder is limited range of motion. While many shoulder conditions can cause pain of the joint, frozen shoulder is also characterized by significant stiffness.
- Difficulty with Activities
Many typical activities, such as brushing hair, putting on shirts/bras, fastening a seat belt, can become very difficult. The most common problem is reaching behind your back, and patients often notice that their unaffected shoulder can reach much higher up their back than their frozen shoulder.
Other shoulder conditions may cause difficulty when you try to move your arm, but the key to diagnosing a frozen shoulder is when your examiner also cannot move your arm. For example, while patients with a rotator cuff tear may not be able to lift their arm, their examiner can certainly lift the arm up overhead. In patients with a frozen shoulder, the joint is not just weak, but actually stiff.
Almost always, a frozen shoulder can be diagnosed on physical 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 shoulder arthritis.
An MRI is sometimes performed if the diagnosis of frozen shoulder 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 volume of the shoulder joint, which may be small in patients with a frozen shoulder.
Treatment of a Frozen Shoulder
As with any condition, it is critical that the diagnosis be accurate in order for treatment to be successful. Because frozen shoulder is often misdiagnosed, treatment is sometimes not ideal. Many patients with a frozen shoulder receive treatment for a rotator cuff condition, when that’s not really their problem. Frozen shoulder treatment requires aggressive stretching, and can last many months–even years. Fortunately, most patients with a frozen shoulder are able to recover normal function of the joint. If you feel you are not progressing in the treatment of your shoulder pain, just be sure you not have a frozen shoulder joint that could be causing your symptoms.
Frozen shoulder is most commonly found in patients who are:
Without a clear cause
The last statement is there because most often people have a gradual onset of discomfort. Sometimes patients will remember an event that occurred the first time they noticed symptoms, but this is typically a relatively mild activity. In actuality, these activities are probably not the cause of the frozen shoulder, but rather the first activity that occurred once the patient started to develop stiffness of the joint.
Causes of a Frozen Shoulder
There are several conditions that seem to be risk-factors for patients to develop a frozen shoulder. These conditions are seen much more commonly in patients who are diagnosed with a frozen shoulder, but they are not always present in patients with a frozen shoulder.
Some of These Conditions Include:
- Endocrine Abnormalities
The most common condition seen in patients who spontaneously develop a frozen shoulder are endocrine abnormalities. In fact, some patients with a frozen shoulder have no knowledge of an underlying endocrine abnormality, and it’s only after being diagnosed with a frozen shoulder that they discover an underlying condition. The most common abnormalities are diabetes and thyroid conditions (both hyperthyroidism and hypothyroidism are seen). Patients who develop a spontaneous frozen shoulder should discuss with their primary care physician if further screening is needed for these endocrine abnormalities.
The second most common cause of a frozen shoulder is due to immobilization or trauma. Often called a “secondary” frozen shoulder (as opposed to a primary frozen shoulder) these causes are the result of a traumatic injury, surgery, or other reason for which a shoulder was immobilized. Some patients with shoulder fractures may develop this condition. Another common cause of secondary frozen shoulder is after rotator cuff surgery.
- Neurologic Disorders
Neurologic disorders, such as Parkinson’s Disease, may be present in patients who have the development of a spontaneous frozen shoulder. Much less common than patients with endocrine abnormalities, neurologic conditions can be a risk factor for the development of this condition.
- Cardiac Disease
Cardiac abnormalities, including coronary artery disease and other heart conditions can lead to the development of a frozen shoulder.
While these conditions may make an individual more susceptible to the development of a frozen shoulder, the most common cause a frozen shoulder is “idiopathic,” also known as a fancy way to say, “we don’t know why.”