Ultrasound-Guided First Carpometacarpal Joint Injection Technique

MATERIALS 27-gauge, 1.5-inch needle 3-ml syringe with mixture of 0.5-ml corticosteroid and 1-ml local anesthetic High-frequency linear array transducer (e.g., hockey-stick transducer) Sterile ultrasound probe cover Sterile ultrasound gel Sterile gloves Chlorohexidine or other skin antiseptic 4 × 4 gauze Band-Aid PATIENT POSITIONING The patient is placed in a seated or supine position. The forearm of the affected wrist is placed in neutral position with the radial aspect of the wrist, or thumb side, facing upward. The thumb can be passively flexed to open the carpometacarpal joint space. The provider should position themselves proximal and lateral to the affected wrist with the ultrasound screen in direct view. PROBE POSITIONING The transducer is placed in the anatomic longitudinal plane over the first carpometacarpal joint. NEEDLE TECHNIQUE The injection can be performed using an out-of-plane dorsal-to-palmar approach and walk-down technique. The final needle position should be in between the trapezium and first metacarpal bones at the proximal aspect of the first carpometacarpal joint (Video 1, https://links.lww.com/PHM/C619). Alternatively, the needle can be introduced using a gel standoff technique with an in-plane, proximal-to-distal approach. The ideal approach may depend on the patient’s first carpometacarpal joint anatomy. PEARLS AND PITFALLS Care should be taken to identify the superficial radial nerve which will branch along either side of the joint. Additionally, the practitioner should identify the extensor tendons, as well as the radial artery, which branches into the superficial and deep palmar arteries just proximal to the joint. Avoid injecting excessive injectate into the joint space, which may result in overdistension of the joint capsule.