When is joint aspiration recommended for septic arthritis?

Septic arthritis is an infection inside a joint. It may cause rapid swelling, severe pain, warmth, and difficulty moving the joint; fever may occur but is not required. During aspiration, a clinician removes joint fluid for laboratory testing. The sample can help identify infection and distinguish it from crystal inflammation or another cause. Because damage can progress quickly, aspiration is part of an urgent assessment rather than a routine appointment to postpone.

Go to urgent medical assessment if a joint becomes acutely painful and swollen, especially when movement is difficult or you feel ill. Tell the team about recent surgery, injections, wounds, infections, immune conditions, and medicines. Do not massage the joint or wait for symptoms to settle. The clinician may arrange aspiration, blood tests, imaging, and treatment based on the examination and results.

Seek immediate care for severe joint pain with fever or chills, a hot red joint, sudden inability to bear weight, confusion, faintness, or rapidly worsening symptoms. A recent wound or procedure near the joint increases the need for prompt review. Do not use the absence of fever to rule out infection.

Ask why infection is suspected, which tests will be performed on the fluid, when treatment will begin, and which changes require immediate reassessment.