Establishing an intervertebral disc degeneration model using annulus puncture / 中国组织工程研究

ABSTRACT

BACKGROUND:Annulus puncture method is commonly reported in the establishment of intervertebral disc degeneration (IDD) models, but there is a lack of comparative studies concerning complete MRI, pathologyical and extracellular matrix changes. Thereafter, a further exploration is imperative. OBJECTIVE:To investigate the feasibility of establishing IDD models using annulus puncture. METHODS:Thirty New Zealand white rabbits were randomly divided into two groups (n=15 per group). In experimental group, through extraperitoneal approach, the L1-2, L2-3, and L3-4 intervertebral space were exposed, and then stabbed by 16-gauge hypodermic needles;while rabbits in sham operated group were only subjected to making and incision but not to puncture. Five rabbits in each group were randomly selected for MRI examination at 4, 8 and 16 weeks after modeling, and were sacrificed through air embolism to obtain the nucleus pulposus. Histological changes were observed by hematoxylin-eosin staining, and the level of proteoglycan was detected by Safranin O staining. RESULTS AND CONCLUSION:In the experimental group, T2-weighted signal in the disc was decreased in a time-dependent manner;an obvious reduction was found at 4 weeks after modeling, and reached the peak at 16 weeks. In contrast, the sham operated group showed no significant changes at each time point. Hematoxylin-eosin staining showed that in the experimental group, cartilage-like cells decreased, while fibroblast-like cells in the disc increased in number and proportion, and extracellular fibers were in disorder;all above changes became obvious at 4 weeks after surgery and the most obvious at 16 weeks, but there were no significant changes in the sham operated group. Safranin O staining revealed that the color of the tissues under puncture became lighter, and this variation became overt at 4 weeks after surgery and the most obvious at 16 weeks. In conclusion, annulus puncture is a reliable method to make IDD models.