Research advances on etiology and pathology of Modic changes

Abstract

Low back pain has a serious impact on people's lives in t he world. With the approaching of aging society in China, the number of low back pain increased rapidly. Though many of the pathological factors in spine might lead to low back pain, Modic changes (MCs) was one of the most important factors. Therefore, to get familiar with MCs in the etiology and pathology has a positive practical significance. Although a large number of studies have analyzed the epidemiological and imaging character-istics of MCs, there are relatively few studies on the histological and pathological fields of MCs. In recent years, researchers have gradually shed some light on etiology of MCs and found that low toxic bacterial infection and autoimmune reaction may play a vital role in the development of MCs. The damage of vertebral body or endplate is closely related to the etiopathogenesis of MCs. In ad-dition, to reveal the pathological characteristic of MCs is also a good attempt for better understanding of MCs. There are various im-aging changes in MCs, however, what is the pathological basis behind it. It is also unclear that why different types of MCs are capa-ble of transformation? When MCs occur, the activation of some cytokines (such as IL-6, RANKL, etc.) and certain receptors (TLR, PPARγ, etc.) can interfere with the formation and metabolism of the nearby bone marrow cells, break the balance of formation and absorption in trabecular beam and further change their microstructures through various pathways. During this dynamic balance process, the different types of MCs can be transformed into each other. The specific type may not only depend on the intensity and duration of inflammatory stimulus, but also rely on the composition and metabolic status of the bone marrow. Although the study of animal models has made some progress, some limitations still exist in practical course. Due to the unclear mechanism of MCs, the study on etiology and pathology of MCs may play a great important role in clarifying this issue.