Back Pain Flashcards
Lumbar spine anatomy
https://www.youtube.com/watch?edufilter=NULL&v=0qR-Yfw9fOI
From the side the spine forms…
=3 curves
The neck or the cervical spine curves slightly inward.
The midback or thoracic spine, curves outward. The outward curve of the thoracic spine is called kyphosis.
The lower back or lumbar spine curves slightly inward. An inward curve of the spine is called lordosis.
Lumbar spine
- Made up of the lower 5 vertebrae-L1-L5. L5 connects to the top of the sacrum, a triangular bone at the base of the spine that fits between the 2 pelvic bones (sacrum to pelvis joint=sacroiliac joints)
- Vertebral bodies are taller and bulkier compared to the vertebrae of the rest of the spine. This is partly because the lumbar spine has to withstand pressure from the body weight and from daily actions like lifting, carrying and twisting.
- A boney ring attaches to the back of each vertebral body. When the rings are stacked on top of each other, these rings form a hollow tube called the spinal canal. This boney tube surrounds the spinal cord as it passes through the spinal column.
- Spinal cord extends from brain to L2 giving off nerve roots either side. These nerve roots join together to form the nerves that travel throughout the body. The nerve roots that come out of the lumbar spine form the nerves that go to the lower limbs and pelvis. The thoracic nerves go to the abdomen and chest. The nerves coming out of the cervical spine go to the neck, shoulders, arms and hands.
- Beyond L2, the spinal cord splits into a bundle of nerves that goes to the lower limbs and pelvic organs=cauda equina.
- Spinal segment includes 2 vertebra, the intervertebral disk between them, the 2 nerve roots that leave the spinal cord at that level, and the small facet joints that link each level of the spinal column.
- An intervertebral disc is made up of 2 parts. The centre called the nucleus pulposus, is spongey, and acts like a shock absorber, to cushion the force between each vertebra. The nucleus is surrounded by a series of strong ligamentous rings called the annulus fibrosus (special ligament that connects 2 vertebra together)
- Between the vertebra of each spinal segment are 2 facet joints. The facet joints are located on the back of the spinal column. There are 2 facet joints between each pair of vertebra, one on each side of the spine. A facet join is a small boney knob that sticks out from the vertebral body at the lumbar spine, where these knobs meet they form a synovial joint connecting the 2 vertebra. The facet joints of the lumbar spine move in a slding fashion as you bend forward and backward. Articular cartilage covers each facet.
- As nerves leave spinal cord they pass through a small boney tunnel on each side of the vertebra called a neural foramen.
- The lumbar spine is supported by lumbar ligaments whch are arranged in layers and run in multiple directions where they connect the lumbar vertebrae with pelvis. The muscles of the lower back are also arranged in layers-superficial, middle and deep.
Statistics:
Note on scans: Difference between T1 and T2 imaging
So an MR scan is imaging water. It is the hydrogen ion that has a magnetic quality, it is like a tiny little bar magnet, and because there’s hydrogen in water and that’s where most of the hydrogen your body is. Yes there are hydrogen atoms in other molecules, but it’s predominantly within the fluid in your body, the water. The magnet aligns those little ions in the same direction. So if you lie in the magnetic field, they line up (normally they’re pointing all over the place), but they just line in one direction. You then send a radio signal into the body. It spins those little magnets, the hydrogen molecules. It spins them out of alignment for a transient moment, and then they go back to where they where in the magnetic field. It’s pretty easy to sort of imagine that happening. As they go back, they emit a radio signal and that radio signal takes a certain time to come back. And that is the time constant- how long does it take to come? So not only can we detect where those hydrogen atoms are, we can say how many of them there are in certain area. And at the same time, we can say whether they are tightly bound or not, because the time it takes to relax gives us a number, and that’s the time constant. And that’s why the letter T comes into it. So if we look at the first time constant, we’re going to image solid material, non water. And if we look at the second one, we’re going to image water. And that’s why a T1 image shows water as black, fat however, will be white. On the T2 weighted image, water is white and fat is also white. And that’s the difference between T1 and T2.
- Most get better
- sciatica-meaning pain radiating down leg, could be just thigh or all the way down to the foot.
- sciatica is very common, most recover spontaneously, very few go to surgery.
- 30% are when we get into medical treatment
Definitions:
Non-specific low back pain:
Mechanical low back pain:
Nerve root pain (sciatica):
Non-specific low back pain: no cancer, tumour, inflammatory joint disease, they just have pain, probs from mechanical joints in back. It is saying backpain when we can’t think of anything else, so have to do lots of investigations to find out what it is
Mechanical low back pain: eg lifted something heavy, in car accident and have whiplash etc. Some people refer to it being associated with ligaments and discs etc.
Nerve root pain (sciatica): neuralgic symptoms-burning, aching
Causes of low back pain
-90% mechanical
disc herniation-can press on nerve if unlucky
annular tears-rips within disc, which allow jelly material to leak into outer margin of disc and those chemicals eg prostaglandins, TNF, leukotrienes can be irritant.
Facet joint OA-probs most common
Instability-when wear and tear is so bad that joints begin to slide
Multiple myeloma-lethal if untreated, catch early, not able to treat but can prolong life.
Breast and prostate metastasis
Infection-TB infection of spine
Spondyloarthropathy-inflammatory joint disease eg ankylosing spondylitis. Rhematologist can treat well with biologics. If don’t catch early they will get early. However these are uncommon
Pars interarticularis defects-little bit between facet joints can undergo stress fractures. Common in gymnastics, ballet, repetitive. very important to pick up early as if you stop them doing activity it will heal but if you don’t crack it will get bigger and cause problems.
Compression fracture-jumping from balcony, or osteoporosis so softening of bone and every day activity can lead to fractures.
Visceral pain-pain from body referred to back eg disection of aorta, pancreatitis.
History and physical examination:
Indicators for sciatica:
- Unilateral leg pain greater than low back pain
- Pain radiating to foot or toes (depending on which nerve is affected)
- Numbness and paraesthesia in the same distribution (some nerves are more motor than sensory so may not have these symptoms but they are helpful if do)
- Straight leg raising test induces more leg pain (as raising leg causes stress on trapped nerve causing pain)
- Localised neurology—that is, limited to one nerve root (if sensory area lost can pinpoint to one nerve)
If have pain affecting leg more than back think sciatica
Imaging:
(remember, just guidance)
- Do not routinely offer imaging in a non-specialist setting for people with low back pain with or without sciatica. Reason is that imaging doesn’t help in the slightest
- Explain to people with low back pain with or without sciatica that if they are being referred for specialist opinion, they may not need imaging. MRI-can find things they didn’t know they had and takes money and time. So treat back pain first and only if doesn’t get better take next stage.
- Consider imaging in specialist settings of care (for example, a musculoskeletal interface clinic or hospital) for people with low back pain with or without sciatica only if the result is likely to change management. But in normal clinic don’t do imaging.
Treatment for backpain
- Injections
- Exercise
- Corsets
- Traction
- Manipulation
- Acupuncture
- Ultrasound therapy
- Transcutaneous nerve stimulation
- Psychological therapy
- NSAIDS
- Paracetamol
- Weak opioids
- Opioids=morphine derivatives-addictive, constipation, 2%mortality, (over used in backpain)
- Radiofrequency denervation
- Epidural
- Spinal fusion
- Disc replacement
Red blobs-scientific evidence
Conservative treatment
- Analgesia (Paracetamol)-on a regular basis-this is standard treatment, may ease pain a little bit
- Anti-inflammatory drugs-can prescribe
- Manipulation and physical treatment essetially move muscles and improve alignment of the back. This is helpful in early stages
- Acupuncture-does work in some areas
- Massage-losens muscle spasm, doesn’t treat underlying cause but allows time to pass and most will get better spontaneouly so may help them get through this
- Allow some time to pass
- Bed rest does not result in faster recovery (muscle atrophy, activity actually helps)
- Most patients get better spontaneously
Triage
-Lower back pain
Leg pain
LEARN FOR EXAM!
Red flag for low back pain
weight loss-cancer/infection
fever-infection
night pain-sign it may be something malignant involving bones
Back pain under 19 is extremely rare-indication of urgent MRI, after 19 mechanical is most common.
Insufficent evidence that these correlate, so take this as guidance not rules
Red flags for leg pain-ie sciatica
Cauda equina compression can lead to symptoms shown-Cauda Equina Syndrome
Imaging and treatment straight away (if wait for 12 hours plus will get permanent damage)
Prolapsed intervertebral disc
See tutorial
Waiting too long 1
At top of page is an MRI of the spine, and we can see these patchy changes, so that vertebra is abnormal (black on left image) and it has a white signal on the T2 weighted image. This picture on the left, T1 we call it, it’s a time constant. It shows up fluid as grey, and it shows up fat as white, so the bone marrow in their is white and then there’s fluid in other structures like the spinal canal, which shows up as grey. The picture on the right does the opposite, areas of disease show up as white because it’s water, it’s oedematosus. Also the CSF surrounding the spinal column shows up as white.
So this patchy change is what we see in metastatic malignancy, breast and prostate cancer being 2 of the most common causes. The problem is the bones can become weak, and there’s a risk that they will catestrophically collapse and cause compression of the spinal cord and paralysis. Often people think it is non specific back pain
Inflammatory arthropathy, occurs in young people. We see it in the spine as a ‘shiny corner sign’, so on the water sensitive scans we see this area of oedema, that’s the inflammatory process going on and therefore anyone under 35 will 3 months of pain needs a whole spine MRI-whole spine and sacroiliac joints, to look for this disease.
Waiting too long 2
Myeloma-symtpoms may be very mild, but important to diagnose
TB-vertebral body destroyed and collapsed. Can catch on scan and give anti-TB treatment. In far east disease is gettig resistant to drug.
Imaging for low back pain
On xray can see bone is eaten away here caused by the infection. On CT can see bone eaten away
But MRI shows highest signal of fluid ie pus, shows collapsing vertebra beginning to crush cauda equina and also allows soft tissue to be seen, so this is the best option.
Radiographs-pros and cons
- X-rays are cheaper than MRI
- use moderate radiation
Pagets sarcoma
Can see bowel gas running across. Only sign that you can see if curved spine. Took cross section and can see large mass.
MRI-can see huge paravertebral soft tissue mass. X-ray shows something but its vague, CT shows more but not as much as MRI.
For hip problems though, take x-ray first
Anorexia nervosa
- vertebra looks a bit narrower on x-ray
- Use dexta scan to show low bone density
- MR scan shows crushed vertebra, compression fracture in low vertebra.
Adolescent Disc Prolapse
Slipped disc is the white thing, shown in water sensitive skin as CSF is white. You can always tell by looking at the CSF or urinary bladder, if it’s white, then it’s T2 weighted ie water sensitive. If it’s black or grey, it’s not water sensitive, it’s T1 weighted scanning.
Can see discs contain a lot of fluid which is normal in young people. And we can see on this one that the disc material has punched out backwards, it’s gone through a tear, the annular tear and this soft material has leaked out and there is now a little blob of it protruding out into the spinal canal and pressing on the nerves. This is just the sort of thing that would give sciatica.
When we look in cross-section, we can see this is the bulging disc and these are the nerves, little dots which are now crowded up.
So this is a slipped disc, but this is a 12 year old patient, and adolescent disc prolapse is very rare, that’s why in people under 19 we always do early MRI scans as we often find quite serious conditions in young people
Radiographs miss…
…lesions but so can MRI
Here is a patient with a metastases on the T1 weighted scan. On the T2 or water sensitive scan you can’t see them, son certain MRI scans you may miss them.
3rd pic-broken pars articularis, a stress fracture. Here we see this and we pick it up on MRI because of the bone oedema, white in the bone, and the fracture is the little crack across there. Rest will allow these to heal spontaneously but if leave to late they’ll need operations and potentially will have a life of disability.
4th pic-spinal cord tumour, which is malignant and aggressive, causing veins in area to become serpentine as they are congested. So this is a tumour of the spinal canal coming from the nerves and you can’t see it on an x-ray or CT, it’s invisible but you can on MRI.
Osteoid osteoma
Again white area. It is that little hole in the bone is the tumour. It’s a benign tumour of bone and it is causing this massive reaction of the bone around it. All that white is abnormal and that oedema is abnormal. This occurs in young people.
Treated by ablation and it cures them, done by a single needle puncture under CT scan.
Only the size of a pea maximum
Limited MRI
-80% with degeneration, these would be treated conservatively
Pain Therapy
Facet Injections
Facet Block posterior approach
Root block
CT guided root block
Marker is so we can tell on skin where to start
Fusion imaging a new method-now we use this
Ultrasound on one side mri on other
As move probe, images move
MR and US fusion
US-gets better pic of muscles but MRI gives better of spine
Fused images
Can turn in different planes and angles, good for guiding images
MRI – Ultrasound Fusion Root Block
using VNav needle guidance
Needle sends out radiosignal which is produced on images
Fusion is very precise.
Needle tip=N
T=target
Needle tip=N
T=target
lying on tummy which is why it might be upside down.
Epidural anaesthetic
Dura-hard
Tire is spinal canal, air is CSF
Space between them is epidural space
When not having a baby easier to put needle into epidural space here known as caudal hitaus. CSF actually stops much earlier so there are no nerves no vessels, only fat and a whole.
Epidural is allievitaing pain long enough for spontanous recovery
Surgery
- Decompression of nerve roots
- Decompression of spinal stenosis
- Disc replacement
- Fusion
Tutorial Notes:
X-ray
Patient 63 years old, lateral X-ray on right, bits that go backwards are pedicles
Facet joint-bit between this is pars articularis
Going down joint space is narrowed and bone is whiter showing inflammation. Could just be his age or could be something else, we can’t tell.
Very narrow gap between spinous processes so these start to rub together
We test this by giving local anaethetic at area and if pain goes then we know it is this. Named after Baarstep
MRI
Right is cross section ie axial section and dotted line is where slice is on left
Spinal cord ends in pointy bit known as conus. The nerves then streak across white bit which is CSF.
Nerves are dots on cross section. When it goes through tube it is particularly vulnerable as it is narrow.
Ganglion=thickening in nerve, see yellow bit in pic-this coordinates reflex.
Disc bulging outward can easily trap nerves in the exit foramen.
Facet joints-allow bones to articulate with next one. Allow you to bend, twist and rotate
This patient had lower back pain. When looking at MRI look at bones, spinal cord, aorta, spinal canal, vertebral discs. This MRI was pretty normal for age, tiny bulge mainly, no fractures, tumours, infection, lower discs slightly darker due to normal wear. Problem is you can’t scan pain. If pain but normal scan may well be joint causing issue so put needle into this with imaging guidance and inject local anaesthetic and steroid-diagnostic intervention. If pain goes away, then you know it is that. use a therapeutic intervention to see if we can get a diagnosis. In this case was facet joints.
Basilar vein comes out- see slice bit in middle of vertebral body
Lady 57 with lower back pain and leg pain on left side, running down to outerside of foot.
This is nerve compression symtpoms. We know L5 nerve goes down side of leg to little toe area so we can work out which nerve is compressed. Check reflex eg ankle jerk is S1 so if diminished, something is squashing nerve higher up. We are suspicious of a prolapsed disc in this lady
Disc looks black as annulous fibrosus but and bit in middle is whiter as jelly bit-nucleosus pulposus.
As l5 nerve is passing out it is trapped by slipped disc. 2-nerve, 1-protrusion from disc.
Mostly this goes away by itself, but check for red flags.
Need to help her put up with it. Start with analgesics then give nerve root block injection if goes on for ages. Use fusion imaging.
If doesn’t work may do another one, but if still doesn’t phone surgeons
66, had hip replacement and had really bad back pain and this is his MRI scan
MRI is imaging of water
- he has an old spine, lots of wear and tear
- he has narrowed disc space
- he has osteophytes-boney protections
- Narrowed spinal canal, trapping nerves
First-injected the joints and he got an hour relief but then it came back, so that means he has something else. tried facet joins, tried nerve that might be trapped.
Can see bone oedema in vertebral body (white bit). Did biopsy using CT guidance and we grew Staph aureus. he’s on long term intravenous antibiotics via indwelling catheter and it usually takes 6 months.
