腰椎退行性疾病及其引发的腰痛常见于临床，特别是中老年患者。作为重要临床观察指标，腰椎终板Modic改变（MCs）被认为是腰椎退行性疾病的表现之一。但目前对MCs的研究多集中于临床相关问题，而没有相应的动物模型以更好地探讨其发病机制。研究显示，MCs提示了终板微损伤或椎间盘退变的发生；也有人认为MCs是低毒性细菌感染所致。因此我们提出假设：单纯终板损伤或低毒性细菌感染可用于诱导MCs动物模型。本团队预实验成功建立了经皮穿刺椎体终板损伤动物模型，因此，本研究拟对新西兰兔以经皮穿刺方式进行单纯终板损伤，或于腰椎间盘内或终板区域接种低毒性痤疮丙酸杆菌（P.acne），并设置假手术及空白对照组，以模拟MCs。通过MRI、Micro-CT三维重建、生物力学、分子生物学及免疫组化等方法验证MCs模型，并对终板损伤或低毒性细菌感染诱发MCs的过程进行研究。本研究将首次从动物模型角度研究MCs及其机制。

Lumbar degenerative diseases are common in clinic, especially in aged population. As an important signal in MRI, Modic changes (MCs) of lumbar vertebral endplate are considered to be a typical sign for lumbar degenerative diseases. But nowadays, most studies on MCs are focussed on their clinical characterises and relationship with other diseases, rather than its own mechanism, for there is no proper animal model for MCs. Some clinical studies revealed that MCs are correlated with endplate micro-fracture and intervertebral disc degeneration. Some other researchers consider them to be a result of low virulent bacterial infection, but their theory is still controversial. Therefore, we assume that endplate damage or low virulent bacterial infection can lead to MCs in an animal model. Our preliminary test has successfully established a percutaneous endplate puncture animal model. New Zealand White Rabbits will be used to establish an animal model via simple endplate damage or propionibacterium acnes (P.acne) injection percutaneously, and sham/vehicle will be used as control. MRI, Micro-CT and 3D-reconstruction, biomechanical analysis, biomolecular analysis and immunohistochemical examination will be used to evaluate whether endplate damage or P.acne infection can induce MCs. The roles of endplate damage and bacterial infection in the overall process of MCs will also be discussed. This proposed research will be the first attempt to establish an animal model of MCs and study its mechanism.