Diagnostic Tests For Osteoarthritis

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[edit] Diagnostic Tests For Osteoarthritis

X-rays will show typical changes of the adjacent bone called osteosclerosis. There often are osteophytes visible and possibly bone cysts in the bone adjacent to the joint. Blood tests can be done to rule out other causes such as gout, where the uric acid level would be high, or rheumatoid arthritis, where the sedimentation rate and the rheumatoid factor would be high.

All these tests tend to be normal with osteoarthritis. However, with osteoarthritis of the finger joints there is a characteristic distribution of degenerative changes on X-rays. The hand/finger joints have three levels that can get affected. The first level are the MCP joints (=metacarpophalangeal) between the hand and the fingers (commonly called the "knuckles").

The next row of joints are called the PIP joints (=proximal interphalangeal) and the last row at the end of the fingers are called DIP joints(=distal interphalangeal). Typically with osteoarthritis degenerative changes are confined to DIP joints and PIP joints, but not the MCP joints. This distribution pattern will tell the physician along with the characteristic X-ray changes mentioned above that this person suffers from osteoarthritis. In rheumatoid arthritis there is a more proximal pattern with sparing of the PIP and DIP joints. In the end stages of osteoarthritis there is a complete loss of the joint space due to a loss of the cartilage layer of the joint. Bone is now rubbing on bone. No wonder that these patients are having excruciating pain!

Diagnosis:

The diagnosis is made on the basis of the history, the clinical examination, the X-rays and possibly by ruling out other underlying conditions that may contribute to osteoarthitis. For instance, the rare condition of hemochromatosis could lead to osteoarthritis in a young patient where normally osteoarthritis would not be expected. Treatment of this condition, when diagnosed, could prevent the worsening of osteoarthritis. Acromegaly due to an adenoma of the anterior pituitary gland can also cause osteoarthritis, which will respond by taking care of the underlying growth hormone overproduction. There is also a hereditary type II collagen defect and other hereditary connective tissue abnormalities (dysplasias) that can cause osteoarthritis. Unfortunately physicians do not have all the answers to these conditions.

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References:

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