Magnetic resonance imaging (MRI) is often used to look for tumors, infection, or disc herniation as a cause of low back pain. Vertebral marrow and endplate changes are used to classify the spine as stable or unstable. Marrow is the soft tissue found in the hollow center of bones. The endplate is a piece of cartilage between the disc and the vertebral bone.
Modic Type 1 (MT1) changes seen on an MRI of the spine are considered unstable. Modic Type 2 (MT2) changes indicate a stable spine with no sign of ongoing changes occurring. MT0 is used to describe normal disc and vertebral bone. This method for classifying vertebral marrow and endplate changes was devised by Dr. M. T. Modic in 1988 and used ever since.
In this report, two cases of Modic changes called conversion are discussed. Both patients had degenerating discs in the low back at the L5-S1 level. Repeated MRIs showed MT2 (stable) changes transformed or converted into MT1 (unstable) changes. The patients did not report any change or increase in back pain or other symptoms during the conversion.
Both patients had surgery to remove the disc. An artificial disc replacement was inserted with complete relief of painful symptoms. Relief from chronic back pain was still sustained three years later in both cases.
The authors use this study to point out that MT1 and 2 changes may not really reflect the true situation. MT2 changes may not be as stable or unchanging as previously thought. When it comes to patient symptoms, MT1 and MT2 changes can be equally painful and disabling.
The authors also report the results of other studies that found MT changes can convert from MT1 to MT2 (unstable to stable). Less often conversion occurs from MT1 to MT0 (unstable to normal). Rarely, MT2 converts to MT1 (stable to unstable).