Why is back pain such a misunderstood and so often misquoted topic in the field of spinal surgery? The biennial meeting of the British Association of Spinal Surgeons was held in Norwich and threw up some interesting discussions. The award for best paper went to “ Spinal fusion versus non-surgical treatment in patients with chronic low back pain: an average 11 year follow-up of three randomised controlled trials” presented by Anne Manion, the primary author, from Switzerland. This paper analysed the long term outcomes in the patient group originally reported by Fairbank et al in the Medical Research Council funded study comparing surgery with non-operative management of non-specific back pain. The original article being “Randomised controlled trial to compare surgical stabilisation of the lumbar spine with an intensive rehabilitation programme for patients with chronic low back pain: the MRC spine stabilisation trial.” http://www.bmj.com/content/330/7502/1233
The concern is that already in the description of these papers, confusion is creeping in as to whether we are talking about back pain or non-specific back and that differentiation is crucial.
Unfortunately the chair of the session was unable to allow time for this paper to be questioned adequately by the audience due to limited time left from previous discussions, which is often a risk at meetings. This meant that a number of statements of the paper were left unquestioned and there is a risk this will mean the statements will be misquoted in the future or potentially the authors will go on to publish this paper without adequate challenge. There is no doubt that the authors have made a thorough attempt at gathering and presenting the data they have but they have fallen into a similar trap as others have when quoting the original paper by Fairbanks et al. The term chronic back pain is used in these groups when the implication at various stages in the presentation and papers is that the authors mean non-specific chronic back pain. This distinction may be inferred but by not clarifying this, it results in incorrect interpretation of the results.
The difficulty here boils down to limited consistency in the spinal surgical community when considering and evaluating back pain and the use of the terms chronic back pain or non-specific chronic back pain. Although back pain is clearly only a symptom, it has crept into conversation as a reference to a potential diagnosis, which is where things get so confusing. If non-specific back pain is a diagnosis where no specific cause can be found for the symptom of pain, we should assume all appropriate modern imaging and potential diagnostic techniques have been utilised in establishing the diagnosis or more accurately, our inability to establish a diagnosis. Unfortunately we are simply not consistent in the diagnostic approach. There is too much disagreement among spinal surgeons and allied professions in how to investigate someone presenting with back pain and in the how much effort is placed in establishing the underlying pathology leading to this symptom. This is often due to surgeon training, expertise or surgical interest but may also take into account access to specialist modern imaging such as dynamic weight bearing/ dynamic x-rays, SPECT-CT scanning, availability and expertise in performing diagnostic injections, specialist interpretation of radiological investigations, and finances available to allow specialist investigations to take place. Surgeons may also have varying abilities in surgical techniques to treat certain conditions and we know the inconsistencies among surgeons in suggesting a surgical technique for a particular condition. We may therefore expect to see one surgeon with experience in minimally invasive fusions for single level degenerative discs differ in opinion from a surgeon with experience with disc replacements who may differ further from a surgeon with a practice predominantly in paediatric deformity. The difference may lie in the diagnostic methodology and surgical treatment options considered appropriate. The concern with the original high quality RCT by Fairbanks et.al. was that the inclusion criteria were those patients from a large region where the local surgeon was not sure if surgery should be considered and so included a range of pathologies, a range of surgical interests and expertise as well as a limited number of fusion techniques available when the trial was originally performed. Many of the patients who were expected to do well with fusion surgery were already excluded. So although the paper set out to compare patients with back pain, we are unclear about what pathologies existed. They were aiming to compare non-specific back pain treatments but may have included a number of patients with clearly identifiable causes of back pain for which we know surgery has a favorable outcome. The implications of this are important in that if this is quoted in academic argument, the quote must be accurate. Also if this follow-up paper is quoted it needs to be very clear what these patient groups were. I do not believe that the authors of these papers set out to deceive, but rather it is the specialties unclear understanding and inconsistent terminology used when referring to the symptom of back pain which has resulted in repeated misquotes of the original paper and therefore potentially with subsequent papers dealing with this patient group.
We as a specialty regularly use back pain inferring a diagnosis or pathology when we all know this is a symptom often associated with a range of conditions and should not be used any more than chest pain should be considered a diagnosis or always imply a myocardial infarction.
It is important to get this correct and more attention should be paid to using the term non-specific back pain when it is clear all possible specific causes have been excluded. We should also ensure we are consistent with our diagnostic approach and terminology. We need to move away from the term chronic back pain unless we are very clear what is meant by this symptom. If outcomes of surgery are expected to be good, it is going to be essential to monitor the treatment of patients presenting with back pain and follow them up in the long term being clear what the underlying cause of pain was and what specific operation has been used to treat this. We need to also be clear what is meant in each case in the literature so that the outcome of a minimally invasive L4/5 interbody fusion for a patient with a single level degenerative disc is not compared to a patient with no identifiable pain source on MRI, CT SPECT or after diagnostic injections or provocative tests. In either group, some surgeons may have decided to consider performing a fusion whereas another group may have suggested a functional restoration program and non-operative approach. We haven’t even started discussing what suggestions may be made in considering which surgical approach or technique is to be utilised or the intensity and duration of the functional restoration program. No doubt such a discussion will keep us busy for some time too.
Mr Neil Orpen, Consultant Spinal Surgeon, Great Western Hospital, Swindon, UK
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