Experimental model of intervertebral disc degeneration by needle puncture in Wistar rats

Abstract

Animal models of intervertebral disc degeneration play an important role in clarifying the physiopathological mechanisms and testing novel therapeutic strategies. The objective of the present study is to describe a simple animal model of disc degeneration involving Wistar rats to be used for research studies. Disc degeneration was confirmed and classified by radiography, magnetic resonance and histological evaluation. Adult male Wistar rats were anesthetized and submitted to percutaneous disc puncture with a 20-gauge needle on levels 6-7 and 8-9 of the coccygeal vertebrae. The needle was inserted into the discs guided by fluoroscopy and its tip was positioned crossing the nucleus pulposus up to the contralateral annulus fibrosus, rotated 360° twice, and held for 30 s. To grade the severity of intervertebral disc degeneration, we measured the intervertebral disc height from radiographic images 7 and 30 days after the injury, and the signal intensity T2-weighted magnetic resonance imaging. Histological analysis was performed with hematoxylin-eosin and collagen fiber orientation using picrosirius red staining and polarized light microscopy. Imaging and histological score analyses revealed significant disc degeneration both 7 and 30 days after the lesion, without deaths or systemic complications. Interobserver histological evaluation showed significant agreement. There was a significant positive correlation between histological score and intervertebral disc height 7 and 30 days after the lesion. We conclude that the tail disc puncture method using Wistar rats is a simple, cost-effective and reproducible model for inducing disc degeneration.

Assessment of Intervertebral Disc Degeneration Based on Quantitative Magnetic Resonance Imaging Analysis

“…Our experiments revealed similar histological changes as described by other groups[16, 17, 23, 24], which progressed from one to three months. The punctured and collagen-injected groups showed a narrowing of NP tissue with a decline in NP cells and matrix resulting in an increased matrix-to-cell ratio.…”

Coil optimization for low-field MRI: a dedicated process for small animal preclinical studies

“…Moreover, it was particularly valuable to easily localize a specific disk and to be able to observe five of them at a time. 10,12 The intervertebral disks of these rats was measured at approximately 25 AE 2 mL (the voxel volume being about 0.23 mL), which was in accordance with literature. 36 …”

“…The degeneration of the caudal intervertebral disks is frequently monitored using MRI. [10][11][12] But this kind of study is usually performed using clinical or preclinical high-field MRI devices (>3 T). Low-field MR was therefore envisaged for this study as well as for the lagomorph study.…”

T1ρ and T2 Mapping of the Intervertebral Disk: Comparison of Different Methods of Segmentation

“…This is especially true in cases of severely degenerated disks, when the border zone between the NP and AF becomes indistinct with progressive incorporation of nucleus pulposus material into the interior of the annular lamellae. [16][17][18] PDS-6 and PDS-5B results for T2 and T1 were statistically similar to those of WDS in the nondegenerated group. Our results suggest that about 50% of the disk structure needs to be segmented so that the results would be comparable with those extracted via WDS on intervertebral disks with Pfirrmann grades I and II.…”