[Pseudogout: a contribution to laboratory diagnosis].

Calcium levels of synovial fluid were determined before and after addition of sodium citrate in a group of 15 patients with pseudogout syndrome. 15 patients with osteoarthritis served as control group. In 12 of the patients with pseudogout the calcium levels were statistically significantly different from the controls. the authors have reviewed the clinical, radiological and laboratory aspects of pseudogout and discussed the possible pathophysiological mechanisms which could account for the difference in calcium levels following the addition to the laboratory diagnosis of pseudogout syndrome.