Background

Arthrocentesis (synovial fluid aspiration) can be performed diagnostically (for identification of the etiology of acute arthritis) or therapeutically (for pain relief, drainage of effusion, or injection of medications).^{[1, 2]} The clinician performing the procedure should be familiar with the anatomy of the specific joint in order to avoid puncture of tendons, blood vessels, and nerves.^[3] Using the extensor surface of the joint for needle insertion, while keeping the joint in minimal flexion, minimizes the risk of such injuries.

The ankle joint is a hinged synovial joint with primarily up-and-down movement (plantarflexion and dorsiflexion). However, when the ranges of motion (ROMs) of the ankle and subtalar joints (talocalcaneal and talocalcaneonavicular) are taken together, the complex functions as a universal joint. For more information about the relevant anatomy, see Ankle Joint Anatomy.

Indications

Diagnostic indications for ankle arthrocentesis include the following:

• Evaluation of monoarticular arthritis^[4]
• Evaluation of suspected septic arthritis^[5]
• Evaluation of joint effusion
• Identification of intra-articular fracture
• Identification of crystal arthropathy^[6]

Therapeutic indications include the following:

• Relief of pain by aspirating effusion or blood
• Injection of medications^[7] (eg, corticosteroids, antibiotics, anesthetics)
• Drainage of septic effusion

Contraindications

There are no absolute contraindications for ankle arthrocentesis.

Relative contraindications include the following:

• Suspected septic joint - In this case, no contraindications exist
• Cellulitis overlying the joint - If arthrocentesis is performed, the patient should be admitted for intravenous antibiotics, even if the synovial fluid is not suspicious for infectious arthritis
• Skin lesion or dermatitis overlying the joint
• Known bacteremia
• Adjacent osteomyelitis
• Uncontrolled coagulopathy
• Joint prosthesis - Preferably, a joint prosthesis is tapped by an orthopedist