II. Technique
- Wright's Stain for cell count with differential
III. Labs: Normal Synovial Fluid
- Less than 200 White Blood Cells (WBC) per mm3
- Polymorphonuclear Leukocytes (PMN) less than <50%
IV. Labs: Non-Inflammatory fluid - 200 - 2000 WBC/mm3
- Osteoarthritis or Degenerative Joint Disease
- Trauma
- Osteochondritis Dissecans
- Rheumatic Fever
- Chronic gout
- Chronic Pseudogout
- Progressive Systemic Sclerosis (Scleroderma)
- Polymyositis
- Systemic Lupus Erythematosus (SLE)
- Neuropathic Arthropathy (Hemorrhage may be present)
- Erythema Nodosum
- Pigmented villonodular synovitis
- Hypertrophic Osteoarthropathy
V. Labs: Inflammatory fluid - 2000 - 50,000 WBC/mm3 (mild < 20,000)
- Rheumatoid Arthritis
- Psoriatic Arthritis
- Ankylosing Spondylitis
- Acute Rheumatic Fever
- Acute gout
- Acute Pseudogout
- Progressive Systemic Sclerosis (Scleroderma)
- Polymyositis
- Systemic Lupus Erythematosus (SLE)
- Reiter's Syndrome
- Inflammatory Bowel Disease Arthritis
- Fungal Infections
- Viral Infections
- Bacterial Infections (partially treated)
VI. Labs: Septic fluid - Over 50,000 WBC/mm3 (especially >100,000, PMNs >75%)
- Septic Arthritis until proven otherwise
VII. Reference
- Kolba (1984) Prim Care 11:211-8