Q: I have been suffering from shoulder pain for several months. The pain and stiffness are gradually getting worse. I finally had to stop lifting weights and playing tennis. But now the pain is waking me up at night, and it's hard to raise my arm above my head. I don’t recall injuring my shoulder. What could the problem be?
A: There are quite a few possibilities.
The shoulder is the most mobile joint in the body, and has multiple components vulnerable to painful overuse, injury or arthritis.
Inflammation of any of these areas can cause pain and limited range of motion, so you’ll need to start with getting an evaluation including a physical examination to figure out where the problem is.
There are two joints in the shoulder. The acromioclavicular (AC) joint is between the tip of the scapula (shoulder blade) and the collarbone. The glenohumeral joint is between the humerus (upper arm bone) and the scapula.
Unlike the deep hip socket, the shoulder joint has a much shallower socket called the glenoid (on the shoulder blade). It is lined with cartilage (the labrum) where it interfaces with the humeral head. The rotator cuff muscles and tendons stabilize the shoulder joint in the socket as well as rotate the shoulder. There is a fluid-filled synovial bursa sac that lubricates and cushions this joint space. The biceps muscle attaches to the shoulder in two places and helps control motion at the shoulder and elbow.
The strongest muscle in the shoulder is the deltoid which help rotate, flex and lift your arm. Injuries or inflammation of any of these structures can cause shoulder pain, stiffness and diminished range of motion.
In your case, in the absence of an acute injury, overuse of your shoulder (especially repetitive overhead activities like playing tennis or weight lifting) and aging may result in inflammation, tendinitis, gradual deterioration and eventually tearing of the rotator cuff.
A torn rotator cuff often causes night pain, especially if you sleep on the affected side. If there are arthritic spurs or a deformity of your acromion (where the AC joint creates a bony arch over your rotator cuff), this deterioration may be accelerated.
Sometimes the rotator cuff becomes so inflamed that your tendons thicken, and can become trapped under the bony acromial arch causing impingement syndrome. Impingement syndrome is a common cause of shoulder pain and difficulty raising the arm.
If your fluid-filled bursa becomes inflamed, it can cause painful bursitis, and possibly to development of calcium deposits. Chronically inflamed shoulders may develop fibrous adhesions over time that eventually completely immobilize the shoulder (adhesive capsulitis or frozen shoulder).
Osteoarthritis is another common cause of shoulder pain, especially if you had an old injury that damaged your cartilage. Osteoarthritis may also cause night pain, weakness and limited range of motion.
A torn labrum may cause pain, locking or clicking, and accelerate the development of arthritis.
There are other diseases that can cause shoulder pain like rheumatoid arthritis, lupus, or referred pain radiating from your gallbladder, liver, heart or a herniated cervical disc, to name a few, but your history doesn’t really support any of these.
Depending on your history and physical examination, your doctor may want to do X-rays, an MRI, a CT scan, an arthrogram, or blood tests for more specific diagnostic information.
Treatment options include applying ice or heat, TENS (transcutaneous electronic nerve stimulator), electric stimulation (for muscle weakness or pain), physical therapy (including a home exercise program to continue stretching and strengthening and prevent recurrence).
Activity modification including rest from aggravating repetitive activities like tennis and weight lifting is advisable.
But you must maintain the range of motion so you don’t get progressive weakness and further limit your range of motion. Ask your physical therapist or doctor how much you can use it and don’t immobilize the joint or wear a sling unless specifically told to do so.
You can take over-the-counter acetaminophen or NSAIDs (non-steroidal anti-inflammatory drugs) like ibuprofen or naproxen if tolerated. In some cases cortisone shots may be helpful.
Some serious shoulder problems that do not respond to conservative management may require surgery such as arthroscopy to remove bone spurs, repair rotator cuff tears, or to resect a severely arthritic AC joint (arthroplasty).
In extreme cases, partial or complete shoulder replacement surgery may be necessary.