Lumbar Disc Herniation
Lumbar disc herniation occurs when one of the cartilage discs between the vertebrae in the lumbars pine protrudes and irritates one of the spinal nerve roots that make up the sciatic nerve.
It gives rise to sciatic pain in the leg which can be severe and impact quality of life.
It is one of the five most common surgeries and the major benefit of the surgery is to relieve pain, which in over ninety per cent of cases is immediate. For everyone else, it takes a little longer.
Lumbar Disc Herniation Webinar for GPs:
In this webinar I explain the condition, diagnosis, examination, surgery and post-operative recovery in more detail; it also includes a Q&A session with GPs.
- Presentation (27 min).
- Live Q&A (5 min).
Click below to view the recording.
Click here to download the PDF slides.
The transcript of the webinar is also below.
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lUMBAR DISC HERNIATION Webinar transcript:
Good morning, everyone. My name is Ralph Stanford, and thank you for joining me today to talk about lumbar disc herniation.
Sciatica is pain in the lower limb on one side. The pain is neuropathic, so tingling, numbness, crawling ants, stabbing, sharp, and it'll be dermatomal, so the pain should radiate to a recognized dermatome. The most common affected one is L5, which is on the lateral side of the calf, goes around the ankle and across the top of the foot.
And true sciatica really is one nerve root. If you've got more than one nerve root involved, then there may well be more significant processes going on.
So, disc herniation is obviously a common cause of sciatica. And from a clinical perspective, we can recognize disc herniation, because of these properties here. So it's an abrupt onset. The provocation is usually minor. So, a minor physical movement like twisting to get out of a car, get out of bed, pick up something light off the floor. It's literally the last straw that broke the camel's back as it were.
The patient is generally speaking healthy otherwise, and they'll complain of pain in the buttock. Buttock pain is a common symptom to all the lumbar nerve roots. They'll say the pain is usually worse when they're sitting, and it tends to be better when they're standing and walking. Not a hundred percent rule, but it's a pretty good guide.
And the experience of back pain is quite variable. Some will have significant back pain and some may have none at all, in association with their sciatica.
Of some note is a buildup to the beginning of the sciatica. It is possible for someone to have an episode of back pain brought on by perhaps lifting something heavier, a bucket of water or a basket of wet laundry, and that'd be followed by back pain.
And maybe a few days, a week later, they'll experience sciatica. One imagines that what's happened then is that the initial physical event caused the annular tear, hence the back pain, but later a small movement just pushed out a disc fragment. So we do see that pattern sometimes. So the pathology of lumbar disc herniation is fairly straightforward.
The annulus fibrosis of the intervertebral discs unfortunately undergoes degeneration throughout our adult lives. Once you've turned 23 or so, it's all downhill. And it's just a question of whether tearing of the annular fibers link up and cause a full thickness tear at some point. And then through that tear will come part of the nucleus pulposus.
And that event of the protrusion, as I said, can be initiated by a relatively minor physical movement in the setting of that previous trauma that's accumulated and caused the annular tear in the first place.
We believe that this herniation process is essentially random. It's like flipping a coin each day, whether you're going to have a herniation or not.
People often ask me, have I done something wrong? And not really. It's just unfortunately part of life. You could argue that disc degeneration has got a significant genetic component to it. I'm not saying that disc herniations are inherited, but there may be some complex genetic factors behind this degeneration itself.
So examination. When we meet these people, I quite often find them standing up in the waiting room rather than sitting down because that's more comfortable for them. They can usually walk around fairly well, but they find sitting uncomfortable. And when we examine them, we find variable amounts of neurological deficit, but usually it's mild and they may well demonstrate a positive sciatic stretch test.
So the sciatic stretch, basically the sciatic nerve runs down the back of the lower limb, comes through the buttock behind the hip joint. And so if you passively flex the hip, with the patient in the supine position, you'll actually stretch the sciatic nerve.
And people have done surgical experiments, if you like, where they perform the equivalent of a straight leg raise whilst the patient is anesthetized on the operating table and they can see their nerve root through the incision in their back. And the nerve root will slide about a centimeter when you perform this test.
So when you do this test, you're actually pulling down the L5 S1 nerve roots, a centimeter or so. And you can imagine if the nerve root is trapped over a disc protrusion, that will aggravate the patient's symptoms. So when you do this test, the patient's lying comfortably on their back on your examination bench.
You grasp their heel and you flex the hip passively. You ask the patient to relax. You don't want them to make the movement. Watch their face carefully because if it's painful, you want to stop before you cause too much pain. If you want to accentuate the test of a mild response, you can then dorsi flex the ankle, because that stretches the nerve root a little bit more.
As the tibial nerve passes behind the axis of the ankle joint, it will stretch the nerve a bit more. It's important that when you do this test, you're looking for sciatic pain, pain that goes from the buttock down the limb, much as they're describing in their history. That's a positive test when you reproduce the sciatic pain.
Developing back pain is of no consequence, there's no clinical importance attached to that. If when you flex the hip passively like this and all they get is back pain, then that's a negative sciatic stretch test.
So, putting together a diagnosis clinically on history, the pain will come on fairly abruptly, they won't have any antecedent illness at all related to this, and the pain will be radicular in the sense it will start in their buttock, it will run down their lower limb, it will terminate in a known dermatome. The lateral calf for L5, the shin for L4, and the heel and the sole of the foot for S1. And they'll say this pain is sharp, shooting, tingling, numbness, et cetera. And there's no features of other pathology like a history of cancer or recent infection or anything else going on. This is usually out of the blue.
When you examine them, you'll find evidence of a monoradiculopathy, in other words, a weakness or numbness associated with. So for L5, there would be weakness of toe extension, maybe some weakness of ankle dorsiflexion and altered feeling on the lateral side of the calf and the top of the foot. My feeling is that if it's a clear cut picture like that, they're sudden onset, one nerve root involved, then you can be confident in diagnosing a lumbar disc herniation.
Scans And in the first instance, a scan is not needed to make that diagnosis, and you can treat them on the merits of what you normally would do for lumbar disc herniation. Of course, there might be some things that make you concerned, that might have a significant weakness or some element of the history that makes you worried there's something else going on, in which case, please, by all means, go ahead and arrange a scan, if something concerns you.
But the majority of people, as I'm sure you've met, won't have such complex backgrounds. So, just a brief word on Cauda Equina because, of course, it is related to disc herniation. If a very large disc herniation can cause cauda equina. Of course, cauda equina itself is very rare, but we don't want to miss one.
And in the setting of Sciatica, you might be concerned about it if any of these things crop up. If the patient says they're having difficulty passing urine, they have a tendency to retain their urine, they just can't get their urine out, but different to incontinence, it's more a function of not able to pass the urine fully and their bladder is full.
If they develop bilateral sciatica, sciatica in both lower limbs, and that's a definitely a red flag for potential cauda equina. Of course, if they say they've got numbness in their buttock area and the saddle area, then you should immediately think of cauda equina. And if you wish, then examine their anus and see if there's any sensory loss, or loss of voluntary contraction of the anus.
That then becomes a surgical emergency and they should go straight to an emergency department for immediate care.
So coming back to standard sciatica from a simple disc herniation and natural history.
On the whole, most people will recover by three months, and this has been shown quite a number of times in the literature. So pain will get better, and any mild to moderate sensory or motor loss will also get better in that time frame.
And the long term outlook for lumbar disc herniation is generally favourable. In that, the difference between surgical and non surgical care for acute cytokine is very similar in the long term. So the long term outcomes of surgical and non surgical care are pretty much the same, by which I mean one or two years down the track.
Even then you'll find a few people, maybe a few percent, 5 percent of people will have persistent symptoms regardless of what treatment they had in the beginning, whether it was surgical or not. So whilst it's largely a favourable prognosis, there are occasionally people who just get long term grumbling symptoms of back pain and or some sciatic symptoms.
As I said, if the motor deficits initially are mild, like a grade four out of five, they will usually resolve themselves as well as sensory symptoms. But it's interesting, in my experience, the sensory symptoms are the last symptoms to actually improve. And patients will often come back and say, Oh, I've got a bit of numbness still here. And yes that's true, but it's got no pain. And just reassure them that usually that takes a bit longer to settle down than the other symptoms.
And so from this, you can imagine that most people with Sciatica due to a lumbar disc herniation, really don't need surgery because most of the time they're going to do perfectly well by themselves.
So what about major motor deficits?
If someone comes in with a sciatic pain history and you find on examination they've got a significant motor loss. So by that we mean MRC grade three, so grade three out of five or worse. So it means just anti gravity movement, but not any resistance to your push, or anything worse than that, like a flicker of movement or no movement. In terms of recovery of that, we have very poor evidence in the literature. It's all very much anecdotal or retrospective case series. It's hard to get a prospective series and certainly as far as I'm aware there's been no randomized trial in assessing motor recovery. Lots of randomized trials in terms of pain resolution, but not demonstrating resolution of motor weakness.
So you can see here that for significant motor loss, the rate of recovery is a bit over a third, and it's similar between surgical and non surgical care. So, unfortunately, as a surgeon, this is a very ambivalent situation, what to do with a patient who comes in with a significant motor loss, a big foot drop.
There’s some points of literature say that if this has been going on for two months, so six to eight weeks, then it's a done deal. And I think most surgeons would agree with that. If a patient has six to eight weeks of persistent and severe weakness. It doesn't matter what you do, uh, you can't change the outcome.
There's still a small chance it might get better, but I don't believe that surgery would make a difference to that. If you get patients in the earlier phases, a couple of weeks, three weeks, then maybe surgery has a role.
So whilst I can't give you any firm evidence based answers on this, I think we have to manage the patient as a person, and if to them the weakness is a very severe problem, like they might be a runner, an athlete, and to them the foot drop is a disaster, and they've had it for two weeks, well, I think then, yes, push ahead and try and get them seen urgently, because there's a chance a surgery will help them, and at that stage in the proceedings, two or three weeks down the line, you could argue that the best possible way to get the strength pack is to operate just based on first principles of getting rid of the pathology to help the nerve recover.
And that's fair enough if the patient believes that their weakness is a major problem. And the younger they are, the better the chances of recovery, by which I mean people less than 40. Once you get over 40, up to 60, then unfortunately age is against you. And, your chance of recovery even with surgery is diminishing.
So on the other hand, some people might say, I'm not too fussed, I really don't want surgery. As they make a choice themselves, there are people like that who just would just put up with what they've got. They really don't want to have an operation. And if you explain to them, well, it's kind of 50, 50, whether you do or not, or they'll say, well, don't, I don't want to operate. So you can use the patient's own level of concern about it as a guide.
So just turning to a sort of review of management, then in my view, someone comes along with the classic sudden onset sciatic symptoms with no complicating factors in the history, and you do an examination, you find a bit of mild weakness and numbness in one dermatome that matches their symptoms, then really you can make a diagnosis of disc herniation without a scan, particularly if I have a positive sciatic stretch test.
And you can manage those people based on that clinical assessment and with appropriate advice and observation, you can say to them, well, look, most likely things are going to get better in the next few weeks. It's going to be very painful for a week or two. And just give them some support and advice.
A very short period of rest, a day or two, but really, we do encourage some activity. Even if they don't go to work, they should try and do a bit of walking around the house, up and down the street, something like that. That's probably better than just lying in bed doing nothing.
If they really want to go to work, if they're motivated to go to work, there's something big on, they're self employed, in actual fact, the risk of going to work even if they're a trades person, doing physical work, plumbing, building, actually clinical outcomes are no worse for people who work with sciatica than people who go home with sciatica.
And this has been studied in bricklayers. So if the patient's motivated to continue working despite their pain, then that's okay. And if they're on their feet, in actual fact, they often find being up and around on their feet is better than sitting down anyway. So don't be afraid to let them work if they want.
In terms of pain relief, well, as you know, we always recommend paracetamol and a non steroid ointment, as long as the non steroid is not contraindicated in the patient. Opioids, I know opioids are all frowned upon, but occasionally you're backed into a corner, and I would think it's reasonable to use your favorite opioid for a short period, no more than two weeks, given the limited script. And explain to them from the outset that this is only for a short term.
Pregabalin lyrica has become very popular. But actually the evidence in Sciatica is that it doesn't make any difference. I know it's prescribed a lot. If patients say it works for them, then terrific. But on the other hand, the evidence is that actually, it doesn't add anything. So leave it up to your own discretion.
By the way, in the elderly. I do notice that lyrica will cause quite significant mental side effects quite rapidly. So I do avoid them in the older population. So if the patient improves, so the most important thing of course is bring them back, see how they're going.
If over the next two or three weeks, four weeks, they start to get better, then I think you're all home and hosed.
I forgot to mention here about therapies, just a little backtrack. So when the patient's in a lot of pain, they often want to know, should I go to the physio, or a chiro?
Well, my view is they can do as they wish, but in terms of evidence, really none of those therapies have been shown to make any difference to acute sciatica. But on the other hand, if a patient has a physio they like or even a chiro they like and it gives them comfort and reassurance to see their physio or their chiropractor or if you yourself have a physio that you like to refer to and you feel that that person can make patients feel better, that's fine, because often it's that interaction at an interpersonal level that helps the patient feel better, even if the physical therapy itself in, in terms of hard evidence, doesn't make any difference. There's certainly no harm in it.
Nerve root sleep injections of cortisone can often be helpful. They do tend to work, but of course they're relatively short lived. But that short period may get them through the time in which they got their worst pain and it helps them recover from their sciatica.
So if people ask, I'm happy to prescribe this for them and just explain that it's a little bit hit and miss, but on the other hand, it's not risky. And if they want one, then that's fine. Some people are very adverse to injections and that's also okay. They don't have to have one. So it's just an option up your sleeve to maybe get people out of a tight corner in terms of pain relief.
So, if on review, the patient's pain is persisting and severe, and it's really interfering with what they need to do. They simply can't work. They can't operate at home. Or they've got some major motor loss when you first see them, then that's when you might consider investigating them further with a view to the potential for surgical intervention.
If you can, MRI is by far and away the better modality in the first instance to look for a cause for sciatica. CT these days is pretty good, but it's not as good as MRI. And I understand that the access to MRI is not as good as CT in terms of cost, but if it's at all possible for the patient to get MRI first up, I would recommend it.
And just bear in mind that the radiation from a CT is not insignificant. And in young people, that's something to think about.
So you're hoping to see a disc herniation that corresponds to the symptoms and signs that you just found on examination. So if you think it's L5 by looking at the patient, examining them and see a disc herniation that's compressing L5, then of course you've got a diagnosis.
Sometimes the disc herniation may not be concordant with what you're looking at clinically and that just makes us scratch our heads a bit, you have to look more closely.
So when would someone benefit from surgery?
So if you're tracking them along and their pain is not getting better and they find the pain is a real problem. If they've got motor deficit, which is significant and of impact to the patient. And usually, if you discuss things with them, they'll self select.
So, if after six or eight weeks of pain, they just can't bear it anymore, that's a reasonable time frame. You can say though, well, if you wait another few weeks, things might still get better. Well, it's up to the patient. They can decide.
So, the majority of patients, it's a question of just offering them what's available. Some will jump at the chance for immediate pain relief with surgery. Others will prefer to hang on a bit. Obviously people with major deficits, you might wish to send along earlier.
The one thing about surgery is we do know that it helps with pain. So even though not everyone needs it, if it comes to it, then surgery is good. It does relieve pain with pretty high level of confidence, 95 percent confidence of pain relief.
And, what do we do? So there are a number of different techniques of performing a lumbar discectomy.
I guess at one end of the scale, there's a traditional open technique. Incision five, six centimeters long, done with loops or the naked eye. You can make the incision a bit smaller with a microscope. Microscope gives you a slightly narrower cones through which you can see everything and it gives you brilliant lighting. So microscope is very useful as a smaller incision, a little bit more, I would say precise in terms of the surgical technique, seeing the disc, the disc protrusion, identifying the nerve roots.
And I use a microscope and I find that very useful. And when we're in there, we just remove a little bit of bone from the lamina. And that just gives us a little bit more room to reach in and gently hold the nerve root back whilst we pull out the disc fragment.
There is also an endoscopic technique, which is becoming more popular now, where a similar direction of approach here, but instead of making a three or four centimeter incision, you make a one centimeter incision and use an endoscope. But the results of all these techniques are identical however long the incision is, as long as the disc herniation is taken out expertly.
And the clinical results after four weeks are identical amongst all techniques. So it doesn't really matter what technique is used, it's as long as that technique is performed expertly.
So post-operatively, usually sciatic pain relief is immediate. Motor recovery might happen straight away, but often it takes a while, weeks, occasionally months.
And as I said, sensory symptoms can hang around for quite a while afterwards, but don't usually cause a patient too much bother once you've reassured them. Often the patients get home the day after surgery.
Recovery, I think they can get back to work in a couple of weeks if it's not too physical. Physical work, I do think they should lay off heavy work for six weeks just to allow their tissues to heal, the annular defect to seal over with some scar tissue.
So after six weeks, I'm happy for them to do as they wish. And they can start doing some exercise at that time as well. Up until that six week time, I encourage people to walk. I think walking is the best way to recover during the early phases. And as I say, at six weeks, they can go ahead and do as they wish.
There is a recurrence rate of around about 10%, after surgery. And also interestingly, even with non operative cases. So people that recover from sciatica spontaneously, supposing eight weeks of pain's all gone, they feel really good. A couple of months later, they could get a second episode or a current episode, and that's about 10%.
We don't know how to stop that. People have tried all sorts of things in the surgical technique to try and prevent that, but it hasn't really reached practical use. So we don't know how to stop that. So it's better just to let the patient keep going, doing the natural recovery and whatever happens, happens.
And you treat the recurrence in exactly the same way as you treat the primary one. Just go through the same evolution.
So I'm happy to take any questions.
Someone’s asking, does everyone who presents for sciatica need a scan?
So my feeling is that in the appropriate clinical situation, you can make a clinical diagnosis Lumbar disc herniation, so a sciatic mono radiculopathy, one nerve root involved, sudden onset, a previously well healthy adult with no historical concerns. You don't have to scan them, but if someone's a bit older, perhaps they may have had a history of cancer. So a woman with breast cancer five years ago, you know, it could be possibly a recurrence of a metastatic recurrence of their breast cancer. If someone's had an infection in the last few weeks, maybe a tooth abscess, a UTI, a skin infection, just consider an infection as a possibility. And then of course, if you're in that situation with an antecedent history of some problems, then you may wish to scan those people early on just to make sure that this is a disc and not something more sinister.
Another question here, what do we do in a significant foot drop?
So if the foot is really weak and they're dragging their toes, then yes, I would jump straight in and get a scan, and you can send the patient along for a consultation with a specialist, and they'll be given the option of surgery. And if it's early in the phase, early in the case, so two or three weeks. four weeks, then maybe surgery's got a role to play in relieving the foot drop. As I mentioned, we can't be certain, but if patient's very anxious and they've got significant deficit, then I think surgery is reasonable in the first few weeks.
So in some of the significant foot drop, I would act on that earlier with an early scan and early referral. As opposed to the person who's just got a bit of mild weakness, grade four weakness.
Okay. Thank you very much for listening today and asking your questions. And we will be in touch again with another webinar in a couple of months. So goodbye and have a good day to everyone.
Posted 22 January 2024
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