A Biochemical And Radiological Comparison Between Three Animal Models Of Disc Intervertebral Degeneration

[Background]The animal model of intervertebral disc degeneration is an important approach to investigate the pathogenic mechanisms relevant to human disc degenerative disease, and it also plays an important role in searching and testing novel interventions. Many researchers have established different models, which can be classified as either experimentally induced or spontaneous. Experimentally induced models can be further subdivided into three categories: (1)mechanically induced (by compression or instability); (2)structurally induced (by injury or chemical); (3)genetically induced (by gene knockout tech). Currently, the disc injury models were widespreadly used. While, the studies which compared the characters between different kinds of injury models are rare. And there are still many arguments about models selection.[Objective] To compared the characters between three kind of injury induced models of intervertebral disc degeneration. To provide some valuable suggestions for selecting disc degeneration models with better fesibility and reproducibility, and make the selection more reasonable.[Materials and Methods]20 New Zealand white rabbits were used to test 4 different disc injury models: anulus punctures using a 22or18-gauge needle, nucleus aspiration using a 22-gauge needle, endplate injury using a 18-gauge needle. Rabbits were killed 2, 4, 8,12 and 24 weeks later. Lumbar spinal magnetic resonance images were assessed using 4 grades of disc degeneration. Plain lateral radiograph of lumbar spine was used to measure the change of disc height, according to the "three center lines method". The water content of the nucleus was measured. Dimethylmethylene blue (DMMB) assay was used to measure the sulfated-glycosaminoglycan content. All of the data was analyzed by SPSS 13.0 (t-test and ANOVA)[Results]According to the results of sulfated-glycosaminoglycan content, water content, disc height change and MRI grades change, it is proved that three injury models were all successfully established.