suffering from Athritis?
Types of Arthritis
Facts about Arthritis
Imaging and Osteoarthritis
Osteoarthritis (OA) is an acquired degenerative joint disease that affects millions of U.S. citizens. It is the most common cause of disability in older adults. While more commonly seen in older people, osteoarthritis, should not be viewed as something “inevitable” or simply being the result of aging; mechanical, genetic, metabolic and other conditions all appear to be contributing factors in acquiring this common condition. Thus osteoarthritis is something that is seen with advancing age, but not necessarily because of getting older.
Osteoarthritis is characterized by a breakdown of cartilage, the shock-absorbing material normally found in our joints. After repeated heavy use the cartilage wears out to the point where it may disappear entirely. Then the bones begin to grind directly upon one another, which is typically associated with pain at that point. Another response to the shifting in joint-loading is that in some areas new bone growth may be stimulated, resulting in what are called bone spurs or “osteophytes.” Thus, many changes in the joints take place, further leading to pain, stiffness, joint deformity, loss of motion, bone hardening (sclerosis) and subchondral cysts (fluid collection in the cracked bone).
Since cartilage does not contain nerves, the pain associated with osteoarthritis often comes from secondary sources such as stretching of the joint capsule, damage to ligaments and tendons, muscle spasm and pressure on the outer covering of the bone (periosteoum). However, when the two joint partners have no cartilage in between them, pain can be excruciating due to the two bones rubbing against each other.
How is osteoarthritis diagnosed?
Osteoarthritis is typically diagnosed by the physician obtaining a thorough medical history from the patient, followed by a thorough physical examination and x-ray studies of the incriminated joint or joints. Surprisingly, many people who show evidence of osteoarthritis may not report any pain or other associated symptoms. In addition, studies show that osteoarthritic joints that appear similar upon examination or x-ray may cause pain in some patients while not in others.1 Listed below is a more detailed description of the imaging tests that your doctor may want to order to determine whether or not you have osteoarthritis. Remember, every person is different, and the decision to obtain an imaging study is based on many factors as best evaluated by your doctor.
Your doctor may want to order a radiograph if he/she feels that you may have sufficiently-progressed osteoarthritis. Radiographs are obtained by passing an x-ray beam through the body and onto a special film. Areas which contain calcium, such as the bones, block the x-ray beam and produce lighter spots on the film. Common radiographic findings would include osteophytes, subchondral cysts, bone sclerosis and narrowing of the joint space. Some advanced forms of osteoarthritis may also show joint subluxation, a condition that occurs when the ends of two bones become shifted and no longer properly align at the joint.
X-rays are useful in that they provide a clear, detailed image of the bones and are quick and easy to perform. They are thus widely used as the current standard to diagnose and monitor osteoarthritis progression over time.2 Since cartilage does not contain calcium, it cannot be visualized on a radiograph. Also, the images are limited to providing a two-dimensional view of the joint, and therefore more than one radiograph may be necessary. Another consideration whether to use x-rays is that there is some radiation exposure associated with this form of diagnostic studies and therefore the risks and benefits will need to be weighed for each individual patient.
Computed Tomography (CT)
CT scans are, in essence a “moving x-ray machine.” The study is performed with the person lying flat on a table while a circular rotating x-ray machine then obtains multiple views of the particular joint or body region. A computer then accepts and converts the information thus gained and “composes” finally a highly detailed, three-dimensional view of the area. Your doctor may want to order a CT if the standard radiograph images are not clear or a three-dimensional view of a particular joint is needed, such as when viewing the knee. CT images will show similar findings as standard radiographs, but with much greater detail and depth of the bones. Smaller bone spurs and more subtle signs of bone erosion and sclerosis may be easier to identify with CT than with standard radiographs. Again, when to choose this form of study depends on each individual patient’s situation and specific considerations. CT scans do emit radiation to the body and so the risks and benefits to each patient must be weighed.
Magnetic Resonance Imaging (MRI)
MRI scans are performed similarly to CT scans, but a magnetic field is used instead of x-rays. Unlike radiographs or CT scans, MRI images will show detailed 3-dimensional views of soft tissue structures, such as cartilage, muscle, ligaments and tendons. Your doctor may want to order an MRI to look for signs of osteoarthritis such as cartilage breakdown, joint swelling, bone degradation and tears in knee menisci. Since a strong magnetic field is used, people with cardiac pacemakers, certain prosthetic devices and other metallic objects implanted in the body are not eligible for MRI.
A bone scan is performed by intravenously injecting a small amount of radioactive dye, which is distributed to the bones and measured for different patterns of uptake. Areas of increased bone metabolism or repair, as seen in osteoarthritis, tumors, fractures, and infections, will take up more dye and appear as dark “hot spots” on the image.
Your doctor may want to perform a bone scan to look for other sources of pain not due to osteoarthritis such as osteomyelitis (bone infection) or bone cancer. Osteomyelitis is a medical emergency that may result in limb amputation if not treated promptly. Certain types of cancer tend to metastastize (spread) to bone. Among metastatic bone cancer, common sources include the prostate in men and the breast in women.
The high sensitivity of a bone scan allows earlier detection of subtle but important findings that may not be seen with other imaging techniques. Since a bone scan cannot tell the difference between what it has found, it is often followed by CT or MRI for confirmation. A bone scan may therefore serve as a good initial “screening” examination when there is sufficient clinical information to go ahead with a bone scan.
What if my x-ray shows evidence of osteoarthritis but I feel fine?
Your doctor may tell you that your x-ray shows signs of osteoarthritis despite the fact that you feel fine. X-ray evidence of osteoarthritis, so-called radiographic osteoarthritis, is quite common and does not mean that you will inevitably experience pain and other symptoms. In fact, many people first find out that they have osteoarthritis after an x-ray is taken, despite the fact that they report feeling fine. Early studies dating back to the 1960’s reveals that while radiographic evidence of osteoarthritis was seen in over 90% of people over age forty, 60% of these people did not report any pain or symptoms.3
These early findings are confirmed with more current data. A recent U.K. study of more than one thousand people over age 45 concluded that no relationship exists between pain and mild/moderate hip osteoarthritis as seen on x-ray. The study also showed that 78% of men aged 45-54 and 30-46% of older age groups with severe radiographic hip osteoarthritis had no current pain.4 A separate study revealed that among people whose radiographs show knee osteoarthritis, the most common form of the disease, 20-60% of these people do not show any physical symptoms.5
A group at the University of California, San Francisco investigated the rate of osteoarthritis progression over an eight year period in 745 women with radiographic evidence of hip osteoarthritis. The authors demonstrated that among the women with hip osteoarthritis, those that did not show any pain or symptoms were much less likely to progress to more severe forms of the disease as compared to women that were in pain.6
What should I do if I am diagnosed with osteoarthritis?
Do not be alarmed if you are told that you have “osteoarthritis.” Remember that many people over age 40 and almost everybody over age 80 have some form of osteoarthritis.1 Rest assured in knowing that you may be over-stressing certain parts of your body and there are things you can do to prevent the condition from worsening. Your doctor can suggest stretches and low-impact aerobic exercises to keep your joints working smoothly. Always exercise at a level that your body can handle without causing any considerable pain or stress. Remember, that daily activity performed at a low/medium intensity is better for your body and joints than occasional heavy, strenuous exercise. An anti-inflammatory diet can also be helpful. See the article on diet for further details.
Keep in mind that pain is a signal the body sends out to let us know when something is wrong. Imagine your hand did not have any pain-sensing nerves and you touched a hot stove…your hand would continue to burn until you looked down and decided to remove it from the stove.
Talk to your doctor about ways to reduce your pain or how you can remain pain-free, and most importantly how to prevent the condition from progressing to irreversible damage.
Remember, “osteoarthritis” is a term used to describe a diagnosis, a brief “summary statement” if you will. The doctor treats you, the person with all your worries, fears, aches and pains, hopes, and your unique life-situation. In the end, the doctor treats YOU and NOT the x-ray.
Authors: Christopher M. Catapano, B.S., New York College of Osteopathic Medicine, Old Westbury, NY
Wolfgang Gilliar, D.O., FAAPMR, New York College of Osteopathic Medicine, Old Westbury, NY
1. Chester, V. New Perspectives on Osteoarthritis. Amer J. Med 1996;100(suppl 2A):10S-15S.
2. Beattie, KA, Boulos, P, Pui, M, O’Neill, J, Inglis, D, Webber, CE, Adachi, JD. Abnormalities identified in the knees of asymptomatic volunteers using peripheral magnetic resonance imaging. Osteoarthritis and Cartilage 2005;13:181-186.
3. Lawrence, JS, Bremmer, JM, Bier F. Osteoarthrosis. Prevelance in the population and relationship between symptoms and x-ray changes. Ann Rheum Dis. 1966;25:1-24.
4. Birrell, F, Lunt, M, Macfarlane, G, Silman, A. Association between pain in the hip region and radiographic changes of osteoarthritis: results from a population-based study. Rheumatology (Oxford) 2005 Mar;44(3):337-41.
5. Lanyon, P, O’Reilly, S, Jones, A, Doherty, M. Radiographic assessment of symptomatic knee osteoarthritis in the community: definitions and normal joint space. Ann Rheum Dis. 1998 Oct;57(10):595-601.
6. Lane, NE, Nevitt, MC, Hochberg, MC, Hung, YY, Palermo, L. Progression of radiographic hip osteoarthritis over eight years in a community sample of elderly white women. Arthritis Rheumatology 2004 May;50(5):1477-86.