Prone position, Single plane fluoroscopy, Lidocaine, Chiba or spinal needles.
Align the endplates at the level of interest (craniocaudal angulation).
Tilt the flat panel with ipsilateral oblique projection to create the scotty dog shape with the superior articular facet (ear of the scotty dog) projecting over the middle of the disk.
Under fluoroscopy, advance a Chiba or spinal needle (e.g. 15 cm, 20-gauge spinal) from paraspinal approach anterior to the facet (ear) and slightly closer to inferior endplate. Aim at the center of disc space using “down the barrel” approach along the fluoroscopy beam until the needle meets resistance (annulus fibrosus).
Lidocaine is administer with a smaller 25 gauge needle, but not with the same needle after accessing the disk (infected materials).
Turn flat panel to frontal projection and advance the needle into the center of the space.
The sample will likely be very small. Prime a short connecting tube with saline, clamp it and connect it to an empty 10-mL syringe. Aspirate from the disk while moving the needle back and forth, the tube priming volume (0.2 mL) is likely to be sucked into the disk and then aspirated. Rinse the tube/syringe with 1-2 mL of saline into a blacktop tube. Remove the needle and rinse it with mL of saline into another blacktop tube.
Routine tests: Fluid culture, GS and anaerobes.
If one needs to confirm the tip of needle in the disk space, a small volume of full-strength contrast can be slowly injected and aspirated. This is probably not recommended in discitis. Normal adult lumbar disc usually takes up to 1.5 mL of contrast.
