You’re at the doctors’ office and you’ve just been told “you have arthritis”. You nod your head knowingly, maybe repeating the term to yourself. But do you actually know what the word means? How about bursitis, or tendinitis? What’s the difference?
Let’s look at these terms in some detail.
First of all, none of these terms is a diagnosis. They only tell part of the story. The suffix, “itis”, implies inflammation, whereas the base of the word refers to anatomy. For instance “arth” refers to a joint, “burs” to a bursa, and “tendin” to a tendon.
“Arthritis”, therefore, means joint inflammation. It doesn’t tell you whether the arthritis is septic (due to infection), crystal (as in gout), inflammatory (as in rheumatoid), traumatic, or the usual “wear and tear” osteoarthritis. It doesn’t tell you where it is, what part of the joint is involved, or what the possible cause is. For example, “patellofemoral osteoarthritis due to malalignment of the extensor mechanism of the knee” is a complete diagnosis. It tells you that the knee cap, as it articulates with the femur bone, is arthritic because the quadriceps-kneecap-patella tendon arrangement is not in true alignment and results in abnormal wear under the knee cap.
The same can be said for bursitis. A bursa is the thin closed sac that usually overlies a bony prominence onto which a tendon attaches. Bursae are found in areas of the body subject to friction. When the bursa becomes inflamed it swells, secretes fluid, and can become quite painful. The term “bursitis” means that the bursa is inflamed, but it doesn’t tell you the cause of the inflammation. To make a definitive diagnosis you need a cause and a location. For example, subacromial bursitis is inflammation of the bursa overlying the insertion of the supraspinatus tendon in the shoulder. The supraspinatus tendon becomes inflamed, it swells, and the bursa is caught between the enlarged tendon and the overlying bony acromion. Being continually pinched, the bursa becomes swollen, secretes fluid and thickens, adding to more impingement. This can result in a very painful “bursitis”.
Tendinitis is a somewhat controversial descriptive term but is commonly used in orthopedics. It implies inflammation where a tendon inserts onto bone. The tendon’s insertion becomes frayed and then inflamed as the body tries to repair it. “Tendinitis” in itself is not a diagnosis, but it does imply that at least part of the condition is due to excess stress at the bone-tendon junction. A classic example is “Tennis Elbow” (lateral epicondylitis) or “Jumpers knee” (patella tendinitis) seen in athletes.
Let`s carry this further, remembering that “itis” implies inflammation: synovitis is inflammation of the lining of a joint; capsulitis is inflammation of the tough fibrous capsule that encloses a joint; fasciitis is inflammation of the fibrous tissue overlying muscle, and neuritis is inflammation of nerve tissue.
The message is that these terms, though helpful, are not a diagnosis, and a diagnosis is what you are after.
Appropriate questions for you to ask when you are told you have “arthritis”, or any of the “itis” family:
What kind is it?
Where is it?
What are the possible causes?
What is the natural history?
What are my options for treatment?