Abstract:

BACKGROUND: Constructing animal model of intervertebral disc degeneration which more faithfully mimics the pathologic hallmarks of human intervertebral disc degeneration can be a beneficial assistance for further intervertebral disc degeneration therapy. However, there is not an accepted optimal model for intervertebral disc degeneration study.
OBJECTIVE: To compare the rabbit model of degenerative intervertebral disc constructed by anulus puncture and anulus incision.
METHODS: Totally 32 New Zealand white rabbits were randomly divided into the anulus puncture group and annulus incision group. Intervertebral disc of L3-6 was exposed by extro-peritoneal approach, and the discs were injured by puncturing the anulus or cutting the anulus. The deep and direction were controlled. Pathological change of intervertebral disc was checked with MRI and histopathological examination at weeks 2, 4, 12, and 20 after operation.
RESULTS AND CONCLUSION: At week 4 after operation, the area of nucleus gelatinosus was deflated with enlarged anulus fibrosus, T2-weighted image (T2WI) declined, blurred, and the height of intervertebral space was also decreased, the grade of T2 value in the anulus puncture group was lower than that of the annulus incision group (P < 0.05); with time prolonged, T2 scores increased, and the intervertebral space narrowed, which reached a peak at week 20 after operation. The differences had no significance. The histological sections demonstrated that the cell content in nucleus pulposus was increased gradually. The rabbit model of intervertebral disc degeneration can be successfully constructed by the methods of anulus puncture and annulus incision. The degeneration of incision model is more severe than that of puncture model. Anulus puncture method can faithfully mimic intervertebral disc degeneration after damage in human being.