How to perform arthrocentesis of the wrist

Learn how to perform a quick and painless wrist tap with the basic wrist arthrocentesis procedure summarized here.
Last update19th Nov 2020

Anatomy of the wrist

Let's start by reviewing the anatomy of the wrist joint.

The wrist joint is found between the distal end of the radius and ulna, and the first row of carpal bones.

Figure 1. Anatomy of a wrist.

When tapping a wrist, it is important that you insert the needle on the ulnar side of the extensor pollicis longus tendon to avoid injury to the radial artery and nerve. To help you identify the tendon, have your patient give you a thumbs-ups!

Figure 2. Prior to an arthrocentesis of the wrist, identify the ulnar side of the extensor pollicis longus tendon with a thumbs-up.

Ideal positioning for arthrocentesis of the wrist

Now that you’ve identified the tendon, it’s time to properly position your patient for a wrist tap:

  • Patient’s affected arm is resting on a table or stretcher
  • Forearm is pronated (palm facing down)
  • Wrist is flexed 25° downwards
  • Wrist is rotated away from the thumb (ulnar deviation)
Figure 3. Ideal positioning of wrist for arthrocentesis. Patient’s wrist is flexed 25° and rotated away from the thumb.

Once the patient is positioned, you will stand in front of the affected wrist to perform the arthrocentesis procedure on the wrist joint.

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How to perform arthrocentesis of the wrist

The arthrocentesis procedure requires five simple steps to ensure a safe, clean, and painless wrist tap:

  1. Direct a 22 gauge (G) needle at the end of the radius on the ulnar side of the extensor pollicis longus tendon.
  2. Aspirate as soon as your needle enters the skin.
  3. Stop advancing the needle when you see fluid.
  4. Extract the joint fluid.
  5. Take the needle out and apply a bandage.
Figure 4. How to perform arthrocentesis of the wrist. 1) Direct a 22 gauge (G) needle at the end of the radius on the ulnar side of the tendon. 2) Aspirate as soon as the needle enters the skin. 3) Advance the needle until it fills with fluid. 4) Extract the fluid. 5) Take out the needle, and apply a bandage.

Excellent work! You now know the basic procedure for a wrist arthrocentesis.

That’s it for now. If you want to improve your understanding of key concepts in medicine, and improve your clinical skills, make sure to register for a free trial account, which will give you access to free videos and downloads. We’ll help you make the right decisions for yourself and your patients.

Recommended reading

  • Roberts, J. 2019. “Arthrocentesis”. In: Roberts and Hedges’ Clinical Procedures in Emergency Medicine and Acute Care. 7th edition. Philadelphia: Elsevier.  

About the author

Siamak Moayedi, MD
Associate Professor and Director of Medical Student Education, University of Maryland and Course Director, Essential and Critical Procedures, Emergency Medicine.
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