Basic calcium phosphate is a chemical compound that occurs naturally in the body. This compound can form crystals that cause joint pain and swelling similar to those ofgout (including podagra), calcium pyrophosphate arthritis(previously called pseudogout), or sometimes other joint disorders. Basic calcium phosphate crystals can also form in tendons and connective tissues.
Milwaukee shoulder/knee syndromeis one example of basic calcium phosphate crystal deposition disease. It is a destructive disorder that mostly affects the shoulders and often the knees, with marked and persistent joint swelling, in older women.
Acute pseudopodagrais another joint disorder caused by basic calcium phosphate crystals and can mimic gout. It affects the joints of the big toe and occurs in young women (less often young men).
Symptoms
Basic calcium phosphate crystals cause pain and severe inflammation in and around joints. The crystals occasionally destroy the joints.
Diagnosis
X-rays
Microscopic examination of joint fluid
To check for basic calcium phosphate crystals, doctors takex-rays. These crystals are sometimes visible on x-rays around the joints, and not usually in the joint cartilage.
Doctors may also need to use a needle to withdraw joint fluid (joint aspiration) and test it for crystals. Basic calcium phosphate crystals are small and usually can be seen only with a special stain or a transmission electron microscope.
Treatment
Nonsteroidal anti-inflammatory drugs
Colchicine taken by mouth
A corticosteroid injection into the joint
Basic calcium phosphate deposition disorder is usuallytreated similarly to gout, with nonsteroidal anti-inflammatory drugs(NSAIDs), colchicine taken by mouth, or a corticosteroid injection into the joint (see tableDrugs Used to Treat Gout).
There is no way to completely rid the body of these crystals.
