Antibiotics for back pain? – an update

By 4 December 2015articles
Antibiotics for back pain

Pain from the spine is commonly due to damage to the shock absorbing discs that sit between the bony blocks of the spine or ‘vertebrae’. This can come on suddenly, or develop over several years. Also the small joints at the back of the spine called ‘facet joints’ can become damaged and painful too. In time this will lead to reactivity and tightness or ‘spasm’ in the muscles that support the spine, bringing yet another layer of pain and soreness.

The best radiological investigation to visualize the problem is currently an MRI scan. This shows all of the above structures in some detail. Traditional understanding suggests that the pain is generated by ‘inflammation’. When a structure is damaged white blood cells localise to this area and release chemical messengers that produce the inflammatory response and part of this is sensitization of the little nerves supplying the discs and joints, resulting in pain. This pain is a very basic message to the patient to ‘rest and let it heal’. Of course it is difficult to rest the spine as we need to get up, walk, sit, go to work etc and so the inflammation and the pain continues.

The treatment for the pain has therefore centred around those that treat inflammation, tablets such as Ibuprofen, Naproxen, Diclofenac and many others. If the pain is resistant to these measures then more powerful anti-inflammatory steroids (cortisone) can be injected around the damaged structures to deal with the inflammation and reduce the pain.

Bacteria

In 2013 there was great excitement in the press. A research group from Denmark had looked at some of the other changes shown on the MRI. They investigated the changes shown next to the damaged discs. The appearances on the MRI are described as Modic changes and reflect a structural problem that is well established. These watery changes or ‘swelling’ in the bone had always been associated with the inflammatory response in the discs.

The research group identified that bacteria can be present in such circumstances. The particular bug thought to be causing many of these changes is called Propionibacterium acnes. This bacterium is difficult to find as it requires special conditions to grow or ‘culture’ so that it can be identified.

The team then performed a study where half the patients were given an antibiotic for 3 months and the others given a dummy medication or ‘placebo’. The results suggested that the patients taking the antibiotics improved significantly compared to those taking the placebo.

The news broke in the press and much hype followed. Headlines suggesting that 500,000 back pain sufferers would be ‘cured with cheap and simple antibiotics’ resulted. Some clinicians started treating patients with antibiotics to try and help these patients. Many suffered side-effects whilst on the antibiotics especially relating to the gut and the poor response to treatment in the clinical setting, started raising questions and concerns.

The research data was subsequently reviewed and the study was found to be flawed in several ways. In other words there was not strong evidence that this bacteria was indeed to blame for the changes in the spine and therefore antibiotics were not a treatment for everyone.

This led Professor Greenough (National Clinical Director – Spinal Disorders) to conclude that there was not enough evidence to introduce the antibiotic therapy across the board. Indeed the prolonged use of antibiotics could develop antibiotic-resistant bacteria in the individual patient and the wider community. More research was needed. (see below).

Current therapy

In the last 3 years there have not been data studies to back up the original findings of the initial research paper. There are a small number of patients who develop infections as the principle cause of their spine pain, but certainly not the huge numbers originally suggested.

Perhaps in the fullness of time more evidence will be available but for now this avenue of treatment is not accepted in the mainstream. So for now the long established theory that the vast majority of spine pain is due to damage or ‘wear and tear’ causing inflammation holds true. Therefore the standard approaches to spine pain still apply.

POSITION STATEMENT ON ANTIBIOTICS AND LOW BACK PAIN 2013
Professor C Greenough MD MChir FRCS

There has been a lot of interest in the National Press following the publication of a paper from a group in Denmark concerning the treatment with antibiotics of a highly selected group of patients with low back pain. The group performed a randomised controlled trial and found significant improvement with a 100 day course of antibiotics (amoxicillin/clavulanate, 500mg/125mg). This is a very exciding research finding and deserves urgent investigation. The surgical community will work with researches to prove these findings and to try to further define any group which may respond to antibiotic treatment. However, it must be recognised that a single trial does not produce sufficient weight of evidence to change current practice.

The trial was undertaken in a very specific group of patients as follows:

  • Lumbar intervertebral disc prolapse proven on MRI and treated either conservatively or surgically within the previous six to twenty four months.
  • Significant low back pain of at least six months duration initiated or significantly exacerbated following the disc prolapse.
  • The presence of modic type I changes adjacent to the involved disc (high intensity T2, low intensity T1).

The position

  • Such a prolonged course of broad spectrum antibiotics carries risk of complications in the individual and risk of antibiotic resistance in the community. The evidence at present insufficiently strong to recommend long term course of antibiotics in patients fulfilling these criteria, but further research is urgently required.
  • No patient who does not fulfil all of the criteria should be given antibiotic therapy.
  • Careful consideration should be given to the potential for low-grade infection in patients in this group being considered for back pain surgery.

This position statement will be regularly reviewed.

Professor C Greenough MD MChir FRCS
National Clinic Director – Spinal Disorders
July 2013