By Youyou Duanmu MD MPH, Nicholas Ashenburg MD & Viveta Lobo MD
Atraumatic joint pain and swelling is a common Emergency Department complaint that carries a wide differential. It is crucial for the emergency physician to differentiate between septic arthritis and less emergent etiologies such as degenerative joint disease, tendonitis, gout or calcium pyrophosphate deposition disease.1-2 Septic arthritis can result in significant morbidity and mortality, and requires aggressive treatment with IV antibiotics, orthopedics consultation and possible need for a surgical procedure.3-4
Arthrocentesis provides a definitive result regarding the composition of a joint effusion. However, it can be frustrating for both the patient and provider to pursue this procedure without successful fluid aspiration. Ultrasound visualization of the presence or absence of effusion in small joint spaces such as the wrist and ankle can be a useful diagnostic tool to determine the utility of an aspiration attempt, and to provide static or dynamic guidance of a joint aspiration procedure.5-6 Ultrasound guidance of arthrocentesis has been shown to decrease the time to successful aspiration, to increase the volume of fluid drained, and to increase novice practitioner confidence in the procedure.7-9 Below, we describe the technique for ultrasound guided drainage of the wrist and ankle.
- The techniques for ultrasound guided wrist and ankle arthrocentesis are similar. The choice of in-plane vs. out-of-plane needle approach during dynamic guidance can vary based on patient anatomy/positioning.
- The aspiration site should be cleaned and prepped in usual sterile fashion and sterile gloves should be worn.
- The use of a sterile probe cover (sterile adhesive dressing or complete sterile cover) is recommended if dynamic ultrasound guidance is being used.
- Local anesthetic should be injected under the skin prior to joint aspiration.
Figure 1: Suggested supplies for wrist/ankle joint aspiration. A sterile probe cover can be used as an alternative to the adhesive dressing over the linear probe
1. Position the patient’s hand palm side down with the wrist in slight flexion.
2. Place the ultrasound probe in sagittal position over the distal radius.
Figure 2: Positioning for an in-plane approach for wrist arthrocentesis (sterile procedure not shown)
3. Slide the probe distally until the joint space between the radius and scaphoid or radius and lunate is visualized.
Figure 3: Normal wrist joint (with and without labeled anatomy). C=carpal bone
4. An effusion will appear as a hypoechoic fluid collection above the carpal bone.
5. Use an in-plane, distal to proximal needle approach. Aspirate while advancing needle.
6. Visualize the entire tract of the needle while advancing until the needle tip has penetrated the effusion and observe the decrease in effusion size.
Figure 4: Wrist effusions (highlighted in red). Dotted line represents in-plane needle approach
1. Position the patient’s foot in slight plantarflexion.
2. Place the ultrasound probe in sagittal position at the distal tibia between the medial malleolus and tibialis anterior tendon.
Figure 5: Positioning for an in-plane approach for ankle arthrocentesis (sterile procedure not shown)
3. Slide the probe distally until the joint space between the tibia and talus is visualized.
Figure 6: Normal ankle joint (with and without labeled anatomy)
4. An effusion will appear as a hypoechoic fluid collection above the talus.
5. Use an out-of-plane, medial to lateral needle approach. If possible (adequate patient plantarflexion), an in-plane, distal to proximal approach can be pursued (as shown in Figures). Aspirate while advancing needle.
6. Visualize the needle while advancing until the needle tip has penetrated the effusion and observe the decrease in effusion size.
Figure 7: Ankle effusion (highlighted in red). Dotted line represents in-plane needle approach
- Visualize surrounding tendons and vasculature (using color Doppler) and avoid needle penetration of these structures.
- Even when a joint effusion is present on ultrasound, most wrist and ankle effusions will yield only 1-3cc of fluid.
Special thanks to Ryan Barnes, DO and Bradley Presley, MD of the Medical University of South Carolina for supplying some of the images in this article.
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9. Berona K, Abdi A, Menchine M, et al. Success of ultrasound-guided versus landmark-guided arthrocentesis of hip, ankle, and wrist in a cadaver model. Am J Emerg Med. 2017;35(2):240-244.