A Suprainguinal Ultrasound-Guided Fascia Iliaca Plane Injection Using the Anterior Inferior Iliac Spine Landmark: An Anatomy-Based Technical Report

The fascia iliaca compartment is a potential interfascial space deep to the fascia iliaca and superficial to the iliacus and psoas muscles. Compared with infrainguinal techniques, the suprainguinal approach is anatomically favorable for cephalad spread beneath the fascia iliaca. Although this approach is well established in perioperative analgesia, detailed procedural descriptions adapted for ultrasound-guided fascial hydrodissection and interventional pain practice remain limited. This technical report describes an anatomy-based, ultrasound-guided suprainguinal fascia iliaca plane injection using the anterior inferior iliac spine (AIIS) as a practical sonographic landmark. With the patient supine, a high-frequency linear transducer is used to identify the AIIS and is then rotated into an oblique plane directed toward the umbilicus. In this orientation, the iliacus muscle, overlying fascia iliaca, and adjacent abdominal wall musculature can be visualized. The procedural target is the plane between the fascia iliaca and the iliacus muscle. Under in-plane ultrasound guidance, an echogenic needle is advanced from caudad to cephalad into the interfascial plane. Correct needle-tip placement is confirmed with a small test injectate, followed by incremental delivery of the remaining injectate under continuous visualization. This report emphasizes sono-anatomical orientation, needle trajectory, confirmation of correct fascial plane separation, expected injectate spread, and safety considerations. The manuscript is intended as a technical and educational description rather than as evidence of clinical efficacy. By presenting a reproducible AIIS-based workflow, this report may support clinician training, procedural standardization, and future prospective studies.