Effectiveness and Limitations of Obturator Nerve Block Techniques

Patient Positioning for Ultrasound‑Guided Block

• The American Society of Anesthesiologists recommends performing the ultrasound‑guided obturator nerve block with the patient in a supine position and the leg slightly abducted for applications other than transurethral procedures. 1

Success Rates of Landmark‑Based Approaches

• According to multiple ASA studies, landmark‑based obturator nerve block techniques correctly place the needle adjacent to the nerve in only about 14 % of attempts and are associated with a 45 % overall failure rate, reflecting high anatomic variability and limited reliability of purely palpation‑guided methods. 2, 3, 4, 5, 1, 6, 7, 8