ABSTRACT
BACKGROUND: Rice bodies can occur in the joints in many rheumatic conditions, but they are most common in rheumatoid arthritis. They are generally believed to occur rarely in patients with osteoarthritis, but one study reported rice bodies with apatite crystals. OBJECTIVE: To report on a series of joint fluids with rice bodies containing apatite clumps and examine their clinical pictures. METHODS: All synovial fluid analysis reports for 10 years were reviewed for rice bodies and eight patients were reported on. A series of patients with a variety of diseases with synovial fluid rice bodies found to contain calcific material is described. All were examined by compensated polarised light and alizarin red stain, and four were examined by electron microscopy. RESULTS: The eight patients all had alizarin red S chunks embedded throughout the rice body. Transmission electron microscopy disclosed the presence of a matrix of collagen, fibrin, and amorphous materials containing typical apatite crystals. Clinical diagnoses, radiographic findings, and leucocyte counts varied, but six of the eight patients had had previous repeated corticosteroid injections into the joints. CONCLUSION: Aggregates of apatites may be more common than previously recognised in rice bodies as they are not routinely sought. Whether they are a result of joint damage or depot steroid injections and whether that might contribute to further joint injury now needs to be investigated.
Subject(s)
Apatites/analysis , Arthritis, Rheumatoid/metabolism , Synovial Fluid/chemistry , Anthraquinones , Arthritis, Rheumatoid/drug therapy , Calcium , Child, Preschool , Female , Glucocorticoids/adverse effects , Humans , Injections, Intra-Articular , Knee Joint , Male , Microscopy, Electron , Middle AgedABSTRACT
Aliquots from 30 synovial fluids were submitted to 4 laboratories for comparison of leukocyte counts and differential cell counts, and to 3 laboratories for a search for and identification of crystals. Leukocyte counts showed only fair correlation (coefficients of 0.76-0.80) with the reference laboratory. In synovial fluid from 4 patients, there was sufficient difference in leukocyte counts to cause the fluids to be erroneously classified as either "inflammatory" or "noninflammatory". In 12 of 24 fluid specimens examined, percentages of neutrophils fell outside the 95% confidence limits of the value determined by the reference laboratory. In 7 of the 11 patients with crystals reported, discrepancies were found between the reports from 1 or more laboratories. More attention to quality control of synovial fluid analyses is important.
