8 – Scanning technique

Place the patient in the lateral decubitus position.

Place the low-frequency 6-2 MHz) curved array probe across the iliac crest and parallel shift it medially along the iliac crest until the sacral bone comes into view. In this position the probe is rotated until both the upper margin of the sacral bone and the transverse process of the L5 vertebral body and interspace between the two bony structures come into view.

The intertransverse and lumbosacral ligaments are visualized (see next page).

The needle is inserted with a steep out of plane approach perpendicular to the skin surface and advanced until it penetrates the lumbosacral ligament and a loss-of-resistance is obtained. Electrical stimulation is superfluous.

20 mL of local anaesthetic is injected.