synovial fluid findings in disease states

Laboratory

• Normal
  • appearance: clear to straw colored
  • 0-150 WBC/mm3 (0-0.15 x 10E9/L): neutrophils < 25%
  • no RBC
  • glucose within 10 mg/dL (0-0.56 mmol/L) of plasma glucose
• non-inflammatory conditions
  • appearance: yellow, transparent
  • < 3000 WBC/mm3 (< 3 x 10E9/L): < 30% neutrophils
  • no RBC
  • glucose within 10 mg/dL (0-0.56 mmol/L) of plasma glucose
  • examples: osteoarthritis, traumatic arthritis, neuropathic osteoarthropathy, pigmented villonodular synovitis, early rheumatic fever, early rheumatoid arthritis, early bacterial infection
• inflammatory
  • appearance: yellow, cloudy, turbid
  • 3000-75,000 WBC/mm3 (3-75 x 10E9/L): > 50% neutrophils
  • no RBC
  • glucose may be diminished up to 40 mg/dL (2.22 mmol/L) relative to plasma glucose
  • examples: rheumatoid arthritis, lupus erythematosus, Reiter's syndrome, rheumatic fever, gout, pseudogout, arthritis associated with inflammatory bowel disease, psoriatic arthritis, fat droplet synovitis
• infectious
  • appearance: yellow, purulent, or bloody
  • 50,000-200,000 WBC/mm3 (50-200 x 10E9/L): > 90% neutrophils
  • RBCs present
  • glucose diminished 20-100 mg/dL (1.11-5.55 mmol/L) relative to plasma glucose
  • examples: bacterial, fungal & tuberculous infections
• lymphocytic predominance (up to 20,000/uL)
  • Mycobacterium (tuberculous arthritis)
  • mycosis
  • Borrelia
  • sarcoidosis
• hemorrhagic
  • red-brown or xanthochromic
  • 50-10,000 WBC/mm3 (0.05-10 x 10E9/L): < 50% neutrophils
  • RBCs present
  • glucose within 20 mg/dL (0-1.11 mmol/L) of plasma glucose
  • examples: hemorrhagic effusions associated with traumatic arthritis, pigmented villonodular synovitis, synovial hemangioma, neuropathic osteoarthropathy, joint prostheses, hematologic disorders including: hemophilia, thrombocytopenia, anticoagulation, sickle cell disease or sickle cell trait, myeloproliferative disorder

* SI units in parentheses

Additional terms

• synovial fluid
• synovial fluid analysis