Modic type I endplate change

Modic type I endplate change is the most controversial and important of the three types described (see Modic endplate change).  It is seen on MRI of the spine and represents the presence of low T1 and high T2 signal within the bone marrow of a vertebral body adjacent to a disk. Type 1 change can enhance and be painful.

Modic type I changes are seen much more frequently in patients with low back pain (46%) compared to asymptomatic general population (6%) .

They are believed to be the result of fissuring of the endplates with the development of vascular granulation tissue adjacent to the endplates, resulting in bone marrow edema .

This pattern is very similar to that seen in infection and merely represents bone marrow edema. Without correlation with clinical parameters (symptoms, fever, inflammatory markers) it can be difficult to distinguish sterile Modic type I change from diskitis/osteomyelitis. Highlighting this difficulty is the finding that a proportion of patients which what appears to be 'incidental' Modic type I change will go on to have proven diskitis osteomyelitis by low virulence pathogens such as Staphylococcus epidermidis, Propionibacterium acnes, and diphtheroid species over protracted follow-up (4.2% over 2 year follow-up in one study ).

More controversial is a 2013 study which suggested that patients with isolated Modic I changes on imaging with only chronic lower back pain as a symptom (and no clinical or laboratory evidence of infection) responded clinically to protracted antibiotic administration with statistically significant improvement in disease-specific disability-RMDQ, leg pain and lumbar pain . The authors have coined the term Modic Antibiotic Spinal Therapy (MAST).

A 2015 review of the subject found moderate evidence supporting a causal relationship between the presence of bacteria and Modic I changes, as well as with lower back pain. The authors, however, state that further research is required.