Ultrasound-Guided Arthrocentesis of the Ankle

A nkle effusions can be quite debilitating, causing band-like swelling and stiffness to the anterior aspect of ankle at the tibiotalar joint. Significant swelling can impair ankle dorsiflexion and plantar flexion. The differential diagnosis for joint effusions is wide, and includes traumatic effusion; gout; osteoarthritis; rheumatoid arthritis; and septic arthritis, which is one of the most important diagnoses for the emergency physician (EP) to identify and initiate prompt treatment to reduce the risk of serious morbidity and mortality. Differentiating these conditions requires joint aspiration and synovial fluid analysis. While a large effusion will be palpable and likely ballotable, smaller effusions are more challenging clinically. In such cases, point-of-care (POC) ultrasound can be a valuable tool in confirming a joint effusion.1