Model of Disc Degeneration in Rat Tail Induced Through a Vascular Isolation of Vertebral Endplates

Animal Models of Internal Endplate Injury-Induced Intervertebral Disc Degeneration: A Systematic Review

OBJECTIVE

To systematically review relevant animal models of disk degeneration induced through the endplate injury pathway and to provide suitable animal models for exploring the intrinsic mechanisms and treatment of disk degeneration.

DESIGN

PubMed, Web of Science, Cochrane and other databases were searched for literature related to animal models of disk degeneration induced by the endplate injury pathway from establishment to August 2024, and key contents in the literature were screened and extracted to analyze and evaluate each type of animal model using the literature induction method.

RESULTS

Fifteen animal experimental studies were finally included in the literature, which can be categorized into direct injury models and indirect injury models, of which direct injury models include transvertebral injury models and transpedicular approach injury models, and indirect injury models include endplate ischemia models and vertebral fracture-induced endplate injury models. The direct injury models have a minimum observation period of 2 months and a maximum of 32 wk. All direct injury models were successful in causing disk degeneration, and the greater the number of interventions, the greater the degree of disk degeneration caused. The observation period for the indirect injury models varied from 4 wk to 70 wk. Of the 9 studies, only one study was unsuccessful in inducing disk degeneration, and this was the first animal study in this research to attempt to intervene on the endplate to cause disk degeneration.

CONCLUSION

The damage to the direct injury model is more immediate and controllable in extent and can effectively lead to disk degeneration. The indirect injury models do not directly damage the endplate structure, making it easier to observe the physiological and pathological condition of the endplate and associated structures of the disk. None of them can completely simulate the corresponding process of endplate injury-induced disk degeneration in humans, and there is no uniform clinical judgment standard for this type of model. The most appropriate animal model still needs further exploration and discovery.

Intervertebral Disc Degeneration Models for Pathophysiology and Regenerative Therapy -Benefits and Limitations

Aim:This review summarized the recent intervertebral disc degeneration (IDD) models and described their advantages and potential disadvantages, aiming to provide an overview for the current condition of IDD model establishment and new ideas for new strategies development of the treatment and prevention of IDD.Methods:The database of PubMed was searched up to May 2021 with the following search terms: nucleus pulposus, annulus fibrosus, cartilage endplate, intervertebral disc(IVD), intervertebral disc degeneration, animal model, organ culture, bioreactor, inflammatory reaction, mechanical stress, pathophysiology, epidemiology. Any IDD model-related articles were collected and summarized.Results:The best IDD model should have the features of repeatability, measurability and controllability. There are a lot of aspects to be considered in the selection of animals. Mice, rats and rabbits are low-cost and easy to access. However, their IVD size and shape are more different from human anatomy than pigs, cattle, sheep and goats. Organ culture models and animal models are two options in model establishment for IDD. The IVD organ culture model can put the studying variables into the controllable system for transitional research. Unlike the animal model, the organ culture model can only be used to evaluate the short-term effects and it is not applicable in simulating the complex process of IDD. Similarly, the animal models induced by different methods also have their advantages and disadvantages. For studying the mechanism of IDD and the corresponding treatment and prevention strategies, the selection of model should be individualized based on the purpose of each study.Conclusions:Various models have different characteristics and scope of application due to their different rationales and methods of construction. Currently, there is no experimental model that can perfectly mimic the degenerative process of human IVD. Personalized selection of appropriate model based on study purpose and experimental designing can enhance the possibility to obtain reliable and real results.