Often through school we are thought to render a diagnosis. We memorize the signs and symptoms and collaborate methods of treatment. This conundrum continues on and on in the academic system only to leave us just as adequate as those which have thought us. It’s easy to fall into this spiral and often at times forget to challenge yourself or the opinions of others.
Let’s stop for a minute and think what do we know about back pain? The list of causes can go on and on such as a herniated disc, arthritis or even spondylolisthesis. Maybe there are other culprits such as trigger points, infections and even forms of cancer.
We have now taken things and put them in a nice categorical term. Patients have something to search for when they go home on the internet and insurance companies can make their claims. However, how often do we probe deeper and forget to trace back to what caused the pain in the first place.
If we don’t attempt to understand the origin of pain in the low back we will merely stay at a plateau and not progress as a profession. The key to understanding diagnosis is breaking things down to the specific structure that is causing the pain. No spectrum of symptoms lumped into a group can always answer this question. We merely need to rely on anatomy, histology, chemical processes and pain right down to the cellular level. Not easy is it..?
Bogduk & April being experts in studying pain explore this idea. A list of criteria can be met in order to answer your question.
1. Could it be a source of back pain?
Basically is it actually feasible that a structure can generate pain. To answer this question you have to know does it have a nociceptive nerve supply. Before the 1980’s the disc was not rendered a source of back pain. It wasn’t until studies started to show its nerve supply that the idea of discogenic pain started to evolve. Now studies are looking more thoroughly into discogenic pain (2,3,4). Anatomical studies have rendered muscles, ligaments, vertebrae, synovial joints, intervertebral disc and even fascia as structures with a nociceptive nerve supply.
2. Can it be a source of back pain?
Just because it’s possible for me to run a marathon doesn’t mean I will. Ok stupid analogy but although structures have the capability to produce pain doesn’t mean they will. After all there is no correlation to degenerative disc disease found on a radiograph and the amount of pain experienced by the patient. Furthermore, finding a pars defect to indicate spondylolysis doesn’t always mean it’s what causes the patients pain. Therefore the structure has to be shown to produce pain in a normal non-symptomatic person in order to fulfill this second criterion.
3. Is it ever a cause of back pain?
To understand this question you have to look at things in an epidemiological manner. Think of something you diagnosed a patient with that had low back pain. Now ask yourself..is it possible for an asymptomatic patient to have this problem?? Can a non symptomatic patient have degenerative disc disease or spondylolisthesis?? The answer is yes.
4. Is it ever a source of back pain?
Bogduk & April discuss how pain cannot be seen, cannot be photographed and is subjective. Back pain is barley a lethal cause of death so we never really explore it at the microscopic and molecular level.
Consider that we are often left with forms of imaging that look at macroscopic pathologies. Although, we see degenerative disc disease on an xray it doesn’t show things on the cellular level. It may be that we just have to take this diagnosis and look at it more microscopically to see it as a source of pain. Even if a spondylolysis is evident on radiographs we order a SPECT after to see if the pars defect is active or inactive.
Their opinion is with the use of diagnostic blocking and provocation discography the essence of pain can be explored. However, this form of diagnosis is hard to come by and can be extremely painful. So although we may not have such tools in our office these forms of diagnosing are helping to set the foundation of where pain is coming from. So the next time someone comes in to you with a problem and asks you “Doctor where is the pain coming from”..go ahead try to answer them.
1. Rehabilitation of the Spine: A Practitioner’s Manual 2ed. The Sources of Back Pain: Nikolai Bogduk & Charles April (Chapter). Craig Liebenson (Book). 2007
2. Does Diskogenic Low Back Pain and Leg Pain Exist without Nerve Root Entrapment? David L. Spencer. Approaches to Chronic Pain 1998;67-71
Hurri, H., & Karppinen, J. (2004). Discogenic pain Pain, 112 (3), 225-228 DOI: 10.1016/j.pain.2004.08.016