Ultrasound-Guided Subtalar Joint (Posterior Peri-Achilles Approach) Injection Technique

MATERIALS 21- to 30-gauge 1.5 to 2-inch needle for local anesthesia and injectate 12- to 18-MHz linear array transducer Local anesthetic, steroid, and/or other injectate Sterile ultrasound probe cover Sterile ultrasound gel Sterile gloves Chlorhexidine or other skin antiseptic 4 × 4 gauze Adhesive bandage PATIENT POSITIONING The patient is placed prone on the table, with the foot hanging over the distal edge, and the ankle resting in dorsiflexion. With ergonomic considerations in mind, the provider is positioned posterior to the ankle. The ultrasound screen should be in direct view across from the provider, in direct line with the clinician’s eye line, the transducer, and the needle trajectory. PROBE POSITIONING The ultrasound transducer is placed in a longitudinal-oblique plane over the posterior subtalar joint, just lateral to the Achilles tendon, with the calcaneus visualized as parallel to the transducer as the construct allows. NEEDLE TECHNIQUE The needle is introduced peri-Achilles tendon and is progressed using an in-plane, posterior-lateral to anterior-medial approach toward the subtalar joint. Steep downward angulation is necessary, allowing needle passage superficial to the posterolateral calcaneus. The target needle position is at the subtalar joint between the calcaneus and talus. PEARLS AND PITFALLS The needle can alternatively be introduced using a sterile gel stand-off technique, which may help overcome access difficulties and better allow simultaneous target and needle visualization. Care should be taken to avoid the sural nerve and the saphenous vein, which lay superomedial to the subtalar joint. Video Legends Ultrasound-Guided Injection Video Series: Subtalar Joint, https://links.lww.com/PHM/C605