The shoulder is a complex joint where several bones, muscles, and ligaments connect the upper extremity to the chest. The rotator cuff is a group of muscles and tendons that attach to the bones of the shoulder joint providing movement and stability to the shoulder. Inflammation of the rotator cuff tendons is called rotator cuff tendonitis or shoulder impingement and inflammation of the bursa that surrounds these tendons is called rotator cuff bursitis or shoulder bursitis.
Three bones, namely the upper arm bone (humerus), the shoulder blade (scapula) and the collar bone (clavicle) join to make the shoulder joint.
The acromion is a protuberance of the shoulder bone or scapula. Ligaments are the thick strands of fibers that connect bone to bone. Ligaments connect the collar bone to the shoulder blade at the acromion process.
Bursa is a sac between the acromion process and the rotator cuff. It contains a lubricating fluid which prevents friction between the moving rotator cuff and the acromion.
Rotator cuff bursitis may be caused by repeated minor trauma such as overuse of the shoulder joint and muscles or significant trauma such as a fall.
Rotator cuff tendonitis may occur due to:
- bony growth of the acromion process
- Inflammation of the bursa fluid (bursitis).
- Degeneration of the tendons with age particularly above 40 years’ old
- Overuse injury of the tendons: This occurs more often in people in certain professions and in sports requiring repetitive shoulder movement such as tennis players, swimmers, construction workers, and painters.
- Trauma or injury: one hard throw can cause the problem to occur.
Diagnosis involves physical examination by the doctor. X-rays are ordered to nullify other causes of the pain such as arthritis or to check if shoulder impingement is due to a bone spur. Soft tissues such as muscle and tendons cannot be seen by X-ray so an ultrasound or MRI scan may be ordered to see if shoulder bursitis or shoulder tendinitis is involved.
Your doctor may give an injection of an anesthetic drug in the space below the acromion to see if it provides relief for the pain. If it does, it confirms that the pain was due to rotator cuff tendinitis or shoulder impingement.
Treatment generally involves avoiding overhead activities totally for a time to rest the affected tendons and muscles. Non-steroidal anti-inflammatory medicines are given to reduce inflammation and thus help in decreasing pain and swelling. Some shoulder muscle strengthening exercises are also advised. If this does not provide relief an injection of local anesthetic and corticosteroid, a strong anti-inflammatory agent, may be given in the bursa below the acromion.
The goal of surgery is to create more space for the rotator cuff by removing the front (anterior) edge of the acromion bone and the inflamed tissue of the bursa. The surgery can be done as an open surgery or arthroscopically. In open surgery, a large incision is made in the front of the shoulder to reach the rotator cuff and the acromion. However, in arthroscopy, a minimally invasive surgical procedure, a tubular instrument called an arthroscope and other surgical tools are inserted into the shoulder joint through two or three small incisions. The arthroscope has a camera on the end which allows a large picture of the inside of the joint to be displayed on a television monitor for the surgeon. Once the problem is repaired, the incisions used in arthroscopy are sutured or closed by tape. Advantages of arthroscopy over open surgery are less pain, shorter recovery, and fewer complications.
After the surgery pain medications are administered to relieve the pain and the arm is placed in a sling to allow healing. Your doctor will also prescribe physical exercises of the shoulder to get back functional mobility and strength in the shoulder muscle.