CT-guided injection technique into intervertebral discs in the ovine lumbar spine

Purpose: Disc injection to create intervertebral (IVD) disc degeneration (IVDD) has been reported in ovine models, but the techniques have not been thoroughly described. The current ex vivo study aimed to evaluate a computed tomography (CT)-guided injection technique into IVDs in the ovine lumbar spine. Methods: Insertion of needles into the nucleus pulposus was assessed by gross anatomic dissection in two lumbar segments (group A), and injection of liquid within the disc was assessed by discography in six segments (group B). Results: The pathway of the needle was simulated on computer after an initial CT scan, followed by control of the insertion process via a laser beam and monitoring scans. In group A, 20 insertions were assessed and 17 needles (85 %) were successfully positioned in the nucleus pulposus. In group B of 30 injections, the rate of success was 90 %. Conclusions: The current study provides useful clinical information that will help surgeons working with an ovine model for research on IVDD. This model could also be useful to train less experienced surgeons or radiologists to disc injection. This CT-guided injection seems to offer several advantages such as ease of use, good success rate and safety to important nervous and vascular structures.