Impingement Syndrome - Shoulder (Rotator Cuff Tendonitis, Bursitis)

From Economou SG, Economou TS: Instructions for Surgery Patients.
Philadelphia, WB Saunders, 1998, p. 549.)

From Shankman GA:
Fundamental Orthopaedic Management for the Physical Therapy Assistant St. Louis, Mosby Year Book, 1997, p. 244. © Mayo Foundation.

Description
Impingement syndrome is pain in the shoulder due to inflammation of the tendons of the rotator cuff or the bursa (subacromial bursa) that sits between the rotator cuff and the top of the shoulder (acromion). The rotator cuff is a series of four muscles that surround the ball of the shoulder (humeral head). The subacromial bursa sits over the top of the cuff, allowing for the cuff tendons to slide near the top of the shoulder without undue friction. Normally the humeral head gets closer to the acromion when the shoulder is moved, particularly as you reach overhead. When the rotator cuff becomes inflamed because of injury or overuse, or when the bursa becomes inflamed, then both the swollen tendon and swollen bursa may become pinched between the humeral head and the acromion. Impingement syndrome may represent a grade 1 or 2 strain of the tendon. A grade 1 strain is a mild strain. There is a slight pull without obvious tearing (it is microscopic tendon tearing). There is no loss of strength, and the tendon is the correct length. A grade 2 strain is a moderate strain. There is tearing of fibers within the substance of the tendon or where the tendon meets the bone or muscle. The length of the whole muscle-tendon-bone unit is increased, although there usually is decreased strength. A grade 3 strain is a complete rupture of the tendon.

Common Signs and Symptoms

Pain around the shoulder, often at the outer portion of the upper arm
Pain that is worse with shoulder function, especially when reaching overhead or lifting
Occasionally, aching when not using the arm
Often, pain that awakens you at night
Occasionally, tenderness, swelling, warmth or redness over the other aspect of the shoulder
Loss of strength
Limited motion of the shoulder, especially reaching behind (such as to back pocket or to unhook bra) or across your body
Crepitation (a crackling sound) when moving the arm
Biceps tendon pain and inflammation (in the front of the shoulder); worse when bending the elbow or lifting

Treatment
Initial treatment consists of ice to relieve the pain, stretching and strengthening exercises, and modification of the activity that initially caused the problem. These all can be carried out at home, although referral to a physical therapist or athletic trainer may be recommended. An injection of cortisone to the area around the tendon (within the bursa) may be recommended. Surgery to remove the chronically scarred bursa and spur from the acromion may be necessary, but this is usually only considered after at least 3 months of conservative treatment. Surgery may be performed arthroscopically or with an open incision. Return to full activity is usually possible in 3 months.