Joint Effusion

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Any medical information in this material is intended to inform and educate and is not a tool for self-diagnosis or a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. Please speak to your physician if you have questions about your medical condition.

CC: BY-NC University of Michigan Family Medicine Residency Program. This material is licensed under a Creative Commons Attribution - Noncommercial 3.0 License http://creativecommons.org/licenses/by-nc/3.0/.

(English captions by Trisha Paul from the University of Michigan)

With the patient supine, the leg can be fully extended to assess better for

joint effusion.

Compress the suprapatellar pouch, pushing
the contents distally, and assess for

increased fluid.

Patellar ballottement can also be performed by
compressing the patella and releasing

quickly. Observe for rapid rebound, which
also indicates increased fluid pressure.

If a quicker tap is felt, a larger fusion is present, also called the ballottable

patella.