| Infection | | Bacterial | | Fungal | | Mycobacterial | | Viral | | Spirochete | | Crystal induced | | Monosodium urate | | Calcium pyrophosphate dihydrate | | Hydroxyapatite | | Calcium oxalate | | Lipid | | Hemarthrosis | | Trauma | | Anticoagulation | | Clotting disorders | | Fracture | | Pigmented villonodular synovitis | | | Tumor | | Tenosynovial giant cell tumor (formerly pigmented villonodular synovitis) | | Chondrosarcoma | | Osteoid osteoma | | Metastatic disease | | Systemic rheumatic disease | | Rheumatoid arthritis | | Spondyloarthritis | | Systemic lupus erythematosus | | Sarcoidosis | | Osteoarthritis | | Erosive variant | | Intraarticular derangement | | Meniscal tear | | Osteonecrosis | | Fracture | | Other | | Plant thorn synovitis | |
