Should Arthrocentesis Be Performed in the Noneffusive Knee?

Area of Science:

• Orthopedic Surgery
• Rheumatology
• Diagnostic Procedures

Background:

• Arthrocentesis of a knee joint without effusion is technically difficult.
• A reliable method to obtain synovial fluid from such joints is needed for accurate diagnosis.

Purpose of the Study:

• To evaluate the efficacy of pneumatic compression in improving arthrocentesis success in noneffusive knees.
• To determine if the increased synovial fluid yield is diagnostically valuable.

Main Methods:

• 130 patients with clinically noneffusive knees underwent arthrocentesis with and without pneumatic compression.
• Fluid volume was measured, and success was defined as ≥1.0 mL yield.
• Synovial fluid was analyzed for cell counts, crystal presence, and bacterial culture.

Main Results:

• Arthrocentesis success increased from 15.4% to 53.8% with pneumatic compression (p=0.0001).
• Pneumatic compression increased fluid yield by 460% (0.5 mL to 2.8 mL).
• 60% of aspirated fluids were abnormal, revealing inflammatory arthritis, noninflammatory arthritis, or crystal disease.

Conclusions:

• Pneumatic compression-assisted arthrocentesis successfully yields synovial fluid from clinically noneffusive knees.
• The collected fluid is often abnormal, aiding in diagnosing various joint conditions.
• This technique is valuable for evaluating symptomatic, noneffusive knees.