Construction and evaluation of animal models of endplate injury: a systematic review

PURPOSE: A systematic review of animal models for endplate injury was conducted to identify an appropriate model for investigating the pathophysiological mechanisms underlying endplate injury and its association with low back pain (LBP). METHODS: A comprehensive search of relevant literature was conducted using electronic databases. The identified studies were then evaluated based on predefined inclusion and exclusion criteria. Subsequently, key information and primary experimental findings from the selected literature were extracted and synthesized. This research was performed in accordance with the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). RESULTS: Our study incorporated a total of 10 papers, covering a span of 8 years. Among these, 2 studies specifically induced injury to the endplate and intervertebral disc, respectively. 6 studies involved puncturing the endplate or intervertebral disc followed by the injection of various substances. Additionally, 1 study focused on modeling lumbar instability, while another modeled the tamponade of the nucleus pulposus within the vertebral body. The subjects primarily consisted of mice and rabbits, with 2 studies utilizing mice and 5 studies selecting rats. The remaining 3 studies employed New Zealand White rabbits. The observation period for the experimental models ranged from 4 to 24 weeks postoperatively. The assessment of the animal models predominantly included imaging, behavioral evaluations, histological analyses, and molecular biological tests, with MRI and histological examination being the most frequently utilized methods. CONCLUSIONS: The research has found that endplate Modic changes and endplate injuries are closely related to LBP. Animal experiments provide a model reference for exploring the intrinsic mechanism between the two and the corresponding therapeutic options. Although different modeling methods all induce varying degrees of endplate damage, each has its own advantages and disadvantages. The occurrence process of diseases in animal models is not completely equivalent to that in the human body, and there is currently no unified standard for clinical judgment of such models. Therefore, when choosing an animal model, multiple considerations should be integrated.