Arthrocentesis: MTP (Internal Medicine)

• Diagnostic evaluation of acute monoarticular or polyarticular arthritis
• Therapeutic treatment of acute joint effusions

• Overlying skin infections or lesions
• Arthrocentesis is probably safe in patients with a coagulopathy, unless the coagulopathy is severe. However, the safety of arthrocentesis in patients with abnormal coagulation is not established.
• Bacteremia

• Skin cleansing agent (e.g., chlorhexidine or povidone-iodine)
• Sterile gauze
• Local anesthetic (1% lidocaine is acceptable)
• Small (e.g., 5 mL) syringe with 25-gauge needle for anesthetic injection
• Syringe (5 mL) with 1-inch, 22-gauge needle for joint aspiration
• Specimen tubes for submission of synovial fluid to the laboratory; typically, an EDTA tube is used for cell count and differential, and a lithium heparin tube is used for crystal examination.
• Bandage
• Gloves

• The metatarsophalangeal (MTP) joint is formed by the distal metatarsal and the proximal phalanx of the great toe.
• The extensor hallucis longus tendon is located superiorly and the flexor hallucis longus tendon is located inferiorly.
• Needle entry occurs on the dorsal surface medial to the extensor tendon.
• The anatomy of the interphalangeal (IP) joints of the foot is directly analogous to the IP joints of the hand and to the MTP joint.

Figure 1 :  MTP arthrocentesis

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Figure 3 :  Equipment

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Figure 4 :  MTP Anatomy

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The full content of this section includes:

• Step-by-step text instructions for performing the procedure
  
• Clinical pearls providing practical clinical tips from medical experts
• Patient safety guidelines consistent with Joint Commission and OHSA standards
• Links to medical evidence and related procedures

Figure 7 :  Proper needle placement

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• Monitor for signs of infection in the region.
• Treat suspected septic arthritis before formal diagnosis.
  • The choice of antibiotic may be made empirically or may be based on the Gram stain results.
  • Intraarticular antibiotics are not recommended.¹³
  • The joint capsule must be repeatedly drained until the effusion is cleared. Operative drainage may be needed.
• Treatment of gout
  • High-dose nonsteroidal antiinflammatory agents, colchicine, and oral steroids may be used.
  • Antihyperuricemia treatment should be delayed.
• Treatment of pseudogout
  • Treatment is identical to that for acute gout. Antihyperuricemic agents are not used.

• Complications are uncommon.
• Iatrogenic infection
• Iatrogenic hemorrhage
• Pain during the procedure
• Reaccumulation of the joint fluid