RESUMO
Microscopical study using regular, polarized and electron microscopy, were done in 40 patients with 1ry osteoathritis, for detection of crystals in their synovial fluid and to correlate their presence especially apatite crystals with markers of inflammation detected in their serum and synovial fluids. Eight cases [20%] had negative findings to all types of crystals, 16 cases had calcium pyrophosphate dihydrate [40%] and ten cases [25%] showed Hydroxyapatite crystals. Five cases showed ureate crystals [12. 5%] three of them were accompanied by calcium pyrophosphate dihydrate crystals. Seven cases contained oxalate [17. 5%] three of them were accompanied by other types of crystals [one with hydroxyapatite and 2 with calcium pyrophosphate]. Patients with hydroxyapatite crystals had a significantly higher mean of TLC in their synovial fluids compared to other groups, they also had high mean tenderness score, denoting a possible inflammatory arthritis. It is concluded that [Apatite Associated Arthropathy] detected by electron microscopy was found in a significant number of patients with 1ry osteoarthiritis and their presence could be linked to inflammatory flares in such patients