Anatomy of the shoulder
The shoulder joint is found between the humerus and the glenoid fossa of the scapula. The easiest way to get to the shoulder joint for arthrocentesis is to use an anterior approach. So you will need to landmark the coracoid process which feels like a hard bump just inferior to the acromioclavicular (AC) joint and in front of the humerus.
Ideal positioning for arthrocentesis of the shoulder
For a shoulder arthrocentesis, or shoulder tap, you need to properly position your patient:
- The patient is sitting down
- Their hand (of the affected arm) is in their lap
Once the patient is positioned, you will stand in front of them to perform the arthrocentesis procedure on the affected shoulder joint.
How to perform arthrocentesis of the shoulder
The arthrocentesis procedure requires six simple steps to ensure a safe, clean, and painless shoulder tap:
- Direct your 20 gauge (G) needle just below and lateral to the coracoid process.
- Keep the needle parallel to the floor.
- Aspirate as soon as your needle enters the skin.
- Advance the needle until you get fluid into your syringe.
- Extract the joint fluid.
- Take the needle out and apply a bandage.
Congratulations, you have now covered the basics for how to complete a shoulder arthrocentesis!
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- Roberts, J. 2019. “Arthrocentesis”. In: Roberts and Hedges’ Clinical Procedures in Emergency Medicine and Acute Care. 7th edition. Philadelphia: Elsevier.