Technique

  • Explain the procedure to the patient and obtain informed consent.
  • Position the patient as described above.
  • Identify the olecranon process, lateral epicondyle, and radial head, and find the depression (or bulge, if the effusion is large) found in the soft triangle. This site is used for all approaches.[5] See image below. Triangle formed between olecranon, lateral epicondTriangle formed between olecranon, lateral epicondyle, and radial head as site for needle placement.
  • Identify the site of entry, and mark the site with a plastic needle sheath or sterile marker.
  • Prepare the skin with a cleansing agent and drape with towels.
  • Anesthetize the area by injecting 1-2 mL of lidocaine 1% and forming a skin wheal.
  • Insert an 18-gauge needle into the depression perpendicular to both the skin and radial head from the lateral side. This is the lateral approach, which is preferred.
    • Alternatively, the posterolateral approach can be used. An increased risk of injury to the radial nerve and triceps tendon exists, but this approach is useful if the bulge of an effusion is palpated inferior to the lateral epicondyle.
    • In the posterolateral approach, insert the needle perpendicular to the skin but parallel to the radial shaft. See image below.Aspiration of the elbow, posterolateral approach. Aspiration of the elbow, posterolateral approach.
    • Ultrasonography may aid detection of even a small effusion in the olecranon fossa.[6]
  • Advance the needle slowly while aspirating the syringe until synovial fluid is obtained.
  • If the aspiration is unsuccessful, draw back, reidentify the landmarks, and correct the needle insertion position.
  • If bone is encountered, withdraw the needle slightly and redirect it.
  • Remove the needle when synovial fluid is obtained.
  • Apply a bandage and elastic wrap if a large effusion was present.
  • Place the fluid in specimen tubes and send for analysis.