Indications

To confirm or exclude septic arthritis

To establish the diagnosis in acute mono- or polyarthritis

To relieve symptoms from a tense effusion by draining the joint

Contraindications

Cellulitis of overlying skin

Bleeding disorder (including platelet count <50×10⁹/L, INR >2 or receiving anticoagulant-dose heparin).

Liaise with haematologist as indicated.

Potential complications

Introduction of infection: rarely occurs (<1/10,000) with appropriate sterile technique

Bleeding into the joint in patients with bleeding disorder

Cartilage injury