Mechanical back pain
2008
I have pain through the low back radiating between the legs which is particularly unpleasant and weakness in the legs particularly the left one and inability to sit or stand for more than a few minutes
Question
I am in my early sixties and have had back pain for over 20 years, however the pain has been quite intolerable in the last few years. I have pain through the low back radiating between the legs which is particularly unpleasant and weakness in the legs particularly the left one and inability to sit or stand for more than a few minutes.
Over the past 12 years I have seen about five specialists, had four MRIs and always been told that nothing showed anything major wrong so nothing could be done for me. Last January I was in such pain I saw another specialist who agreed to do a spinal probe. I was told this carried minimal risks and since I was desperate to find out what was wrong I had this done.
When I came round I had severe sciatica in my left leg, the specialist was so surprised as this had never happened to anyone before. The problem turned out to be in my very lowest disc and was extremely painful. On probing the one above was normal. However, following this I did have some improvement in my low back pain and was able to sit for about 15 minutes without being in awful pain. But of course the sciatica was not very pleasant.
I went back again this January and saw another specialist as the former one had retired. He looked at the MRI scan from January 2007 and told me my condition was not suitable to have a spacer put in (the reason for me seeing him). His advice to me was to have a caudal epidural which I am considering. He also suggested that a spinal fusion might be appropriate. I was surprised to hear this because a fusion has never been mentioned to me in all the 20 years I have been seeing specialists.
My general health is poor having lupus, arthritis and some fibromyalgia so I feel I have to be extra careful before embarking on anything too radical. I would be so grateful if Mr Alan Gardner FRCS could give me some advice – I know very little about fusion and even less about caudal epidurals.
Mrs C D – Beds
Answer
I note that Mrs D is 64 and has suffered with her back for some years with back pain worse than some right leg pain suggesting that her pain is mainly ‘mechanical’ rather than relating to nerve compression, which would produce predominant sciatic leg pain.
Having established a diagnostic category we need to try to pin point as far as possible the pain source. The MRI scan suggests that the L5/S1 disc is a likely candidate, which goes with the midline tenderness at that level and the displacement of the vertebra. However L4/5 could also be symptomatic with L3/4 less likely.
We now have a working hypothesis of a diagnosis of L5/S1 discogenic pain, but it is now time to consider the possible options for treatment. These range from a caudal epidural injection which is simple and unlikely to do any harm and has perhaps a 30% chance of producing a worthwhile improvement which may be temporary in which case it can be repeated. Going up the scale, it becomes more necessary to verify the pain source before any more invasive treatment is considered.
Is the situation tolerable or intolerable? Has the local osteopath or physiotherapist had a go? Is the motivation and general health robust enough to consider such treatment?
We are now talking about a controversial investigation called discography, which I have found useful in providing another piece of the jigsaw in some cases. This involves injecting dye into the suspect disc or discs under X-ray control to see if the characteristic pain is reproduced. If it is, then we have reasonable certainty of the pain source. If negative then there is doubt and surgery is less likely to be recommended. A positive discogram suggests the possibility of successful stabilising surgery either with a fusion (immobilisation of the symptomatic disc with bone graft with or without fixation), or, more recently a technique of so-called soft stabilisation without grafting such as dynesys with its relatively quick recovery. However surgery should certainly not be attempted without full discussion of the risks and benefits with your surgeon who has given very reasonable advice.
Chronic back pain is a peculiar animal, which we do not fully understand and the longer it has been present the more difficult it is to shift. There is around a 10% chance of being worse afterwards! Good luck and do let us know what you decide and how things go.