Comment by yourphysio.
The aim of this study was to test the effectiveness and efficacy of Modic Antibiotic Spine Therapy (MAST) in patients with chronic low back pain as well as new Modic Type 1 changes in the vertebrae adjacent to the previously herniated disc.
Type 1 Modic changes are changes that are visible on MRI scans affecting the vertebral bone endplate adjacent to the lumber disc. Specifically, you see bone oedema as a reaction to a process between the 2 tissues. (see the arrows on the 2 contrasted MRI scans in the image).
A disc herniation can result in Modic changes, which, specifically involve disruption and fissuring of the vertebral end-plate (the bonding point of the disc with the bone), reactive bone formation and oedema, and vascular granulation tissue. Infection is one hypothetical cause of the changes seen. In other studies, during surgery, disc material has been removed under sterile conditions, and analysed. It has been found that the material provided evidence of infection with bacteria. It is thought that these organisms gain access to the disc as a result of the process of vascular changes (neovascularisation) associated with disc degeneration and disc herniation.
The ‘Modic changes’ are essentially a ‘side-effect’ in the bone of the inflammation, and this inflammation is proposed to be linked to cytokine and proprionic acid production from the bacterial disc infection.
It is proposed in this study that Modic changes of this kind are present in 35-40% of the back pain population.
It is accepted that Modic Type 1 changes are associated closely with low back pain., and that it is difficult to treat effectively with our current methods.
The results indicated that ‘patients who were in the group that received the antibiotic treatment lasting 100 days reported that pain-relief and improvements in disability commenced gradually, for most patients 6-8 weeks after the start of the antibiotic tablets and for some at the end of treatment. Improvements continued long after the end of the treatment period, at least for another 6 months, and some patients reported continued improvement at 1 year follow up’
There were significant improvements in measured lumbar pain, leg pain, perceived health, number of days of pain, and a reduced number in chronic pain.
At 1 year, a significant decrease in the volume of Modic changes (area of spine observed to be affected on the first MRI scans) was observed.
The paper proposes that the long length of time over which improvements were gained reflects the probability that the healing process only occurs after the bacteria have been killed. It is proposed that the bacteria secrete propionic acid, which has the capacity to dissolvefatty bone marrow as well as bone, and it is this propionic acid diffusion which causes the Modic changes. It is proposed that the reduction in leg pain may be in part due to a diminution of infectious products from the disc capable of irritating nerve roots.
The paper concludes that antibiotics should be considered as a treatment for this subgroup of patients with both chronic low back pain and new modic type 1 changes. when all other treatment options have failed. There is a recommendation to look into this work with those patients who have Modic type 2 changes on MRI scan. There is a consideration of the use of high-dose, long-term antibiotics in the community, and the potential hazards of this approach, and a balanced opinion in the context of the quality of life implications for those who are chronic low back pain sufferers, as well as the medical and socio-economic impact of this condition.