Written by Michael Codsi, MD
Do you ever worry that a pain or ache around a joint may be caused by arthritis? As we age, we tend to associate random aches and pains with arthritis. But what is arthritis exactly, and why does it cause so much pain? Arthritis is a cartilage problem. Cartilage is the ultra-smooth covering on the ends of your bones inside your joints. It is 6 times smoother than ice on ice, and it allows your joints to move without causing you any discomfort. That is, until the cartilage starts to wear out. Once this happens, the bone underneath, which is very rough, becomes exposed. This exposed bone then starts to cause pain, swelling, and stiffness in the joint, all of which we term arthritis. The joint reacts to the arthritis by forming osteophytes, or bone spurs, inside the joint. These spurs can become quite large, and over time they slowly limit the joint’s motion. The spurs can also make a joint look like it is swollen. Arthritis of the collarbone, for example, is easy to see because the joint is close to the skin on top of the shoulder. The shoulder joint, on the other hand, is covered by so much muscle that the bone spurs are rarely seen.
There are many causes of arthritis, including inflammatory disease, traumatic injury, age, and infection. The most common cause is called osteoarthritis. We do not know the exact cause of this disease, but we do know it occurs more commonly as we age. The most commonly affected joints are the hands, followed by the back, knees, hips, shoulders, and ankles. Patients experience pain on the side of the shoulder that is made worse with overhead lifting or reaching to the side or behind the back. When the arthritis becomes severe, it can cause constant pain that keeps people up at night. By that point, most patients have limited motion of the shoulder, preventing them from tucking in their shirts or raise their arms behind their heads.
The diagnosis or arthritis can be made by your doctor after a thorough exam of the shoulder and X-rays. The X-rays will show the arthritis changes in the joint, including the bone spurs. An MRI is rarely needed to make this diagnosis. Unfortunately, an MRI may be ordered before getting an X-ray, because your doctor will be concerned about the rotator cuff. The bone spurs from arthritis can irritate all the structures around the joint, including the rotator cuff and labrum (a ring of tissue around the cup of the shoulder joint), so it is not uncommon for patients to have small tears in these structures in addition to the arthritis. However, it is the arthritis that is causing the pain, not the small tears seen on the MRI, so these small tears do not need to be fixed
There are two different joints in the shoulder that can have arthritis, and your doctor can determine which joint is causing you pain. The main shoulder joint is where your arm meets your shoulder blade; it is a ball and cup-type joint. Arthritis in this joint is not common. The other joint in the shoulder is called the acromioclavicular, or AC, joint. This is the joint between the end of the collar bone and the shoulder blade. The AC joint is close to the skin and can be felt with the fingers in thin patients. Arthritis is commonly seen in this joint, but luckily for most patients, it does not usually cause pain. Arthritis in the AC joint causes pain on the top of the shoulder directly over the end of the collar bone, while arthritis in the main shoulder joint and other shoulder problems cause pain on the side or front of the shoulder.
Treatment for shoulder joint arthritis pain starts with rest, avoidance of painful motion or activities, and heat. Heat can be applied with an electric heating pad or one that is warmed in the microwave. Make sure that any electric heating pad you use has an automatic shut off, so that when you fall asleep in bed, it does not cause burns. If those simple treatments do not work, then over the counter pain medications, like Tylenol, Motrin, or Aleve, can help. Make sure you follow the directions for each medication carefully. If you are taking other medications, ask your doctor to help you chose the best pain medication for you.
There are hundreds of nutritional supplements on the market today. I recommend referring to Arthritis Today (website) to help determine which ones could be useful in treating your arthritis pain.
Another good treatment for arthritis of the shoulder is daily gentle exercise and stretching. The more you move the joint, the less likely it will be to become stiff and tight. However, weight lifting or strenuous activity should be avoided, because it will likely increase your pain and make things worse.
Steroid injections in the joint can help take away pain temporarily. Artificial joint fluid injections for the knee are currently being studied for the shoulder. At this time, however, those injections have not demonstrated any benefits over steroid injections when tested on the shoulder.
If all of the above treatment options have been tried and arthritis continues to cause significant pain in the shoulder, then joint replacement should be considered. Joint replacement is a surgery that removes the worn-out ball and cup and replaces them with a smooth, metal ball and plastic cup. These replacements provide pain relief and allow patients to return to normal life with a few limitations. Most people get 70 to 80% pain relief and shoulder function after they recover from the surgery, which takes 6 months of rehabilitation. There are risks involved with any surgery, depending on the health of the patient.