Osteoarthritis: the physical joint examination

Following a routine exam to assess your overall health, your doctor will feel and press on your problem joints for signs of swelling or tenderness and watching how they work when you walk or bend. Your doctor will also assess other joints that arthritis could could be affecting. This is how a physical exam for osteoarthritis is carried out.

During your joint examination, the doctor will ask you to move joints (known as active motion) and will also move them himself (passive motion). In true joint disease, movement is limited and causes pain with both active and passive motion. If the doctor can move a joint further than you can (flex your knee in a wider arc, for example), then you probably don't have a problem with your joint but instead with the tendons or muscles surrounding it.

Different joints are examined in different ways:

• Hands. The doctor checks for bony enlargements on the end joints of fingers or on the middle joints. These nodes are clear signs of osteoarthritis.
• Hips. Limited range of motion is the key indicator of osteoarthritis here. With the patient lying on his back with knees bent, the doctor places one hand on the knee and the other on the heel and then rotates the foot outward and inward. Restricted inward rotation is typically an early sign of hip osteoarthritis.
• Knees. In addition to checking for abnormalities in joint movement, the doctor looks for areas of swelling around the knee joint.
• Spine. The doctor feels the contours of the spine to check for abnormal tenderness and assesses range of motion — whether the patient can touch his ear with his shoulder, for example.

Osteoarthritis can almost always be diagnosed without the laboratory tests that OA patients routinely undergo. The main reason for these tests is to rule out other possible diseases such as rheumatoid arthritis.

• Blood tests. Some doctors order two blood tests for patients with painful joints: the rheumatoid factor test and erythrocyte sedimentation. These tests can help to indicate whether rheumatoid arthritis is present.
• Analyzing joint fluid. Taking a sample of synovial fluid, removed from the joint with a needle, also helps rule out other possible health problems. Abnormally high levels of white blood cells indicate inflammation and the presence of several possible conditions — including gout, inflammatory types of arthritis such as rheumatoid arthritis or psoriatic arthritis, or arthritis due to an infection (septic arthritis). As a bonus, draining fluid from a joint can help relieve pressure and pain in a joint.

X-rays aren't really useful in diagnosing osteoarthritis, since a significant amount of cartilage must be lost before the damage shows up on an X-ray.

But X-rays of someone known to have osteoarthritis can reveal the extent of the damage. They can show how much cartilage has been lost, whether underlying bone has been damaged, or whether bone spurs are present. In addition, X-rays taken periodically can monitor the progression of osteoarthritis.

Although, interestingly, the severity of a person's symptoms may be totally unrelated to how the joint looks on an X-ray. In fact, only one third of people whose X-rays show the presence of osteoarthritis report pain or any other symptoms. On the other hand, some people whose joints look perfectly normal on an X-ray may have excruciating symptoms from osteoarthritis.

Another imaging technique — magnetic resonance imaging (or MRI) — excels at revealing injuries to soft tissues such as muscles and tendons. But so far, MRI shows no advantage over X-ray systems in evaluating or monitoring joints affected by osteoarthritis.

Keep this information in mind to help ease your nervousness or curiosity around a joint examination. You could also use it to ask your doctor for more information about getting your own joints examined.