Only six studies have reported methods for documenting inflammation in the facet jointss. Studies varied in the precise tissues and phenomena included in the grading systems. However, the systems were generally reliable. Future studies should document the reliability of these methods when independent investigators are not involved in developing the classification schemes. Further work might combine one or more of these measures to establish a standard and reliable grading system for inflammatory changes in the facet joints, including signal intensity within the joint, bone marrow edema, and soft tissue inflammation.