What is it?
Lumbar disc herniation is a common and at times excruciating lower back condition.
Typically the trigger is a minor twisting or lifting action with sudden onset of pain, often in the back and leg together, though in some cases the leg pain may not appear until days later. Sometimes there is no back pain, only leg symptoms. The cause is tearing of the tough, outer annulus of the disc, allowing the soft nucleus to herniate and inflame the nerve that lies adjacent to the disc.
Happily, 80% of adult patients that present with acute sciatica will recover after 12 weeks.
It will be uncomfortable during that time, and that is where your management can reduce patient anxiety.
The diagnosis is clinical, and for the initial treatment period (3-6 weeks), a scan adds little value.
1. The onset is abrupt.
2. The sensations start in a buttock and end at a dermatome on the leg; its location indicates which nerve root is inflamed. For example, L5, the most affected, refers pain to the outer calf and ankle.
3. The pain is described as sharp, shooting, and often accompanied by numbness and tingling.
4. Examination will usually reveal minor changes in strength of affected muscle groups (great toe extension for L5) and accompanying altered sensation in a dermatomal pattern.
5. A final check is the straight leg raise. With the patient lying down, gently lift the heel of the affected lower limb. This elevation extends the sciatic nerve. If it is a disc herniation, the leg pain will increase.
No other pathology presents like this (though I did once see a case of acute diabetic mononeuritis that was just like it, but the MRI was normal and the BSL was 12).
In the initial stages, it comes down to your confidence in diagnosing the condition, coupled with your reassurance of the patient.
1. At this stage, a scan is of little value because it will not change advice. The high recovery rate (80+ per cent) means the initial treatment will be conservative: that is, pain relief and a review of the patient's symptoms in two to three weeks.
Just as important is your reassurance to the patient that this is likely a temporary condition which while uncomfortable, will resolve itself.
2. Pain relief will be individual and dependent upon the patient’s pain threshold. Treatments range from:
- Paracetamol and anti-inflammatories.
- Judicious, limited short term use of opioids such as Panadeine Forte, where appropriate.
- Guided cortisone injections by a radiologist, into the location where the affected nerve exits the spine. For an L4/5 disc protrusion, this means an L5/S1 foraminal injection because that is where the affected L5 nerve root lies. Note: cortisone injections have a 50% success rate, and ‘epidural’ injections do not work.
3. Rest does not help. Light activity, such as standing or walking, is more comfortable than sitting. Going to work is just as good as staying at home.
Should acute pain persist
The rule of thumb is that the pain will decrease sometime between 3-6 weeks. If the pain is still severe after this time, a spinal surgeon consult would be appropriate, and an MRI scan* useful.
At this point, surgery is a reasonable and effective option to be discussed with the patient. However, it requires balanced consideration and my role is to help the patient make an informed decision.
Surgery is effective pain relief from sciatica, but lumbar disc herniation is part of degenerative change in the spine, and back and leg symptoms may persist or recur.
What if there is severe neurological loss?
If you are ever concerned by marked weakness or numbness in the patient, then early MRI* and referral for a spinal opinion is appropriate.
* MRI scans are costly, but don’t let that stop your patient. If it is an issue, do contact my practice on the number below and I will arrange an MRI scan by personal request.
As always if you have any questions about a patient, please feel free to get in touch on 02 9650 4893. I will return your call and discuss how we can help.
You can also reach me via firstname.lastname@example.org.
Dr Ralph Stanford is a spinal surgeon with over 20 years’ experience. He is adept in all surgical approaches to successfully treat his patients.
Dedicated to lifelong learning and sharing his expertise with others, Ralph attends spinal conferences worldwide and regularly consults with colleagues about successful treatments.
As a teacher Dr Ralph Stanford is Conjoint Senior Lecturer at the University of New South Wales; Supervisor of Training for Orthopaedic Trainees, Prince of Wales Hospital; and Education Secretary for the Spine Society of Australia.
As a researcher and scientist, he is a well-published author and Honorary Senior Scientist at Neuroscience Research Australia (NeuRA). He is also a current member of Spinal PFET.
Posted 20 January 2020