Ice temporarily reduces pain from shoulder bursitis.
Shoulder pain can disrupt your daily activities and make it difficult to sleep. The shoulder is a ball-and-socket joint that allows motion in any direction. Because it is so mobile, it is also vulnerable to injury. Bursitis is a shoulder disorder that occurs when the bursa sac -- the padding between the bones and tendons in the shoulder -- becomes inflamed. In some cases, bursitis can lead to frozen shoulder -- a condition that causes it to lock up -- significantly affecting how much you can use it.
The shoulder joint is formed by the humerus -- upper arm bone -- and the glenoid fossa -- part of the shoulder blade. The acromion bone forms a "roof" over the humerus at the top of the shoulder. The main bursa sac in the shoulder -- the subacromial bursa -- sits directly under this bone, padding the space between the bones. The rotator cuff muscles -- supraspinatus, infraspinatus, teres minor and subscapularis -- stabilize the shoulder joint, keeping it in place during movement. Rotator cuff tendons also travel through the subacromial space, and the bursa reduces friction on the tendons with movement.
Bursitis -- inflammation of the bursa sac -- develops when the bursa is repeatedly pinched between the bones in the shoulder. This condition is called impingement, and it is caused by swelling in the subacromial space caused by rotator cuff tendon injury and other trauma to the shoulder. Bursitis can also develop from large calcium deposits in the shoulder joint that cause it to be pinched with movement.
About Frozen Shoulder
The cause of frozen shoulder is not always clear, but it can develop as a result of another painful shoulder disorder, such as bursitis. The shoulder joint is surrounded by a capsule -- connective tissue that keeps the joint together. Frozen shoulder causes the capsule to tighten, progressively reducing the range of motion in the shoulder. People complain of a deep, aching pain and progressive stiffness in the shoulder.
This condition occurs in three phases -- the freezing or painful phase, lasting 3 to 8 months; the frozen phase, lasting 4 to 12 months; and the thawing phase, lasting 12 to 42 months. Most people with frozen shoulder seek medical attention because the condition significantly affects what you can do.
Bursitis causes pain and a decreased range of motion. As a result, you may not be able to move your arm properly or you may avoid moving it. Scarring and thickening of the joint capsule can occur when you're not moving your shoulder, leading to frozen shoulder. Passive range of motion -- when a therapist moves your shoulder -- is not typically limited with bursitis. If you have frozen shoulder, the therapist will not able to move the arm due to joint capsule tightness.
There is no way to predict whether frozen shoulder will develop from a particular person's bursitis, although certain factors -- such as being female, being middle-aged and having diabetes -- are associated with a greater likelihood of developing frozen shoulder.
Early treatment for bursitis and frozen shoulder are similar. Antiinflammatory medications and corticosteroid injections are frequently used. Physical therapy, including heat, ultrasound, electrical stimulation and ice are used to decrease pain and inflammation. Your health care provider may tell you to do range of motion exercises to improve mobility. A therapist may perform manual stretching to improve joint flexibility by stretching the tight capsule.
Frozen shoulder often requires additional treatment to restore your ability to move it, especially if shoulder tightness remains after several months of physical therapy. A manipulation can be performed under anesthesia to break up scar tissue and "un-freeze" the joint. This procedure does not require an incision, and physical therapy typically begins the next day. In some cases, arthroscopic surgery is done to release the capsule. This is a minimally invasive procedure.