Frozen Shoulder Overview
The shoulder is the most mobile joint in the human body offering the greatest range of motion. Certain work or sports activities can put great demands upon the shoulder, and shoulder injuries can occur when the shoulder exceeds movement capacity or the individual structures are overloaded. Frozen shoulder (adhesive capsulitis), also called a “stiff shoulder,” is a condition that can cause a great deal of shoulder discomfort and a limitation of shoulder movement for the patient. In most cases, frozen shoulder results in a complete loss of function and motion of the shoulder. The pain and discomfort, as well the loss of shoulder movement, can become so severe that almost all normal and daily activities become difficult, if not impossible, to do.
Adhesive capsulitis is the technical term used to describe the thickening and tightening of the soft tissue in the capsule (joint lining) of the shoulder joint. This leads to contractures and scarring which results in the loss of motion. Over time, because of the shoulder pain, the shoulder is moved less and less and the stiffness becomes worse. The loss of motion can result in other types of problems such as labral tears or impingment and rotator cuff problems.
What are the types of frozen shoulder?
There are two types of frozen shoulder:
- Primary adhesive capsulitis: Primary adhesive capsulitis occurs when a patient experiences a gradually slow loss of shoulder motion for no apparent reason. It is most common in middle-aged women and is often mis-diagnosed as rotator cuff disease or impingement. The underlying cause of this condition is unknown, but is felt to be inflammatory. It can be EXTREMELY painful. Additional possible causes include changes in the immune system or hormonal imbalances. Diseases such as diabetes mellitus, and some cardiovascular and neurological disorders may also be contributing factors. Primary adhesive capsulitis may affect both shoulders (although this typically does not happen at the same time) and may be resistant to non-surgical treatment. Surgery can effectively help in more severe cases.
- Secondary adhesive capsulitis: Secondary (or acquired) adhesive capsulitis develops from a known cause, such as stiffness following a shoulder injury, a fracture within the shoulder region, a previous unrelated shoulder surgery, or a prolonged period of immobilization. This condition may require surgical intervention when it is more severe.
What are the symptoms of frozen shoulder?
The major symptoms of frozen shoulder are pain and loss of motion. The onset of symptoms may be gradual or sudden, depending on the cause of the condition. Frozen shoulder typically develops in three distinct phases. Each of these stages can last a number of months.
- Freezing Stage: During the freezing phase, the shoulder becomes inflamed and becomes more and more painful. This is sometime difficult to distinguish from shoulder impingement because in the early stages shoulder motion is still preserved. As it progresses, motion becomes restricted. Over time, shoulder stiffness gets progressively worse and shoulder motion will continue to be lost.
- Frozen Stage: Once the freezing phase ends, which may require several months, the shoulder remains stiff but the pain is much less. Gradually over time the stiffness will decrease.
- Thawing Phase: For a classic primary adhesive capsulitis, this phase occurs after 8-12 months and may take 6 months for the shoulder to return to normal. Some patients never enter this phase and many patients with secondary or acquired frozen shoulder never enter this phase.