Leg pain that travels below the knee is a different problem from back pain that stays in the back, and it is worth being precise about the words, because they are used loosely everywhere else.
- Radiculopathy is the finding: a nerve root is irritated or compressed, and it produces pain, numbness, tingling or weakness in the territory that nerve supplies.
- Sciatica is the description most people arrive with — pain running down the back of the leg. It is a symptom, not a diagnosis, and it has more than one cause.
- Disc herniation is one of those causes: material from the centre of a disc pushes out through its outer ring and irritates the nerve root beside it, chemically as much as mechanically.
Getting the distinction right matters because the treatment differs. A herniated disc, a narrowed nerve canal and a nerve being irritated deep in the buttock can all produce leg pain that a patient would describe identically.
Most disc herniations get better without surgery
This is the part that tends to get lost between the MRI report and the surgical consultation. The natural history of a symptomatic lumbar disc herniation is broadly favourable: the herniated material shrinks over time, and the majority of people improve substantially over weeks to months without an operation. Larger extruded fragments, counterintuitively, often resorb more readily than small contained bulges.
That is not an argument for doing nothing. Pain that is severe enough to stop you sleeping, working or walking deserves active treatment, and there is a real difference between waiting well and simply waiting. But it does mean the question is rarely whether to operate and much more often whether the pain can be controlled while the biology does what it usually does.
What the MRI does and does not tell you
Scan a hundred adults with no back pain at all and you will find disc degeneration in most of them, disc bulges in a large share, and frank herniations in a meaningful minority. Those findings increase steadily with age in people who feel completely well.
So a herniation on a scan is not automatically the source of your symptoms. What makes it the source is agreement between three things: the level of the herniation, the distribution of your pain and numbness, and what the examination finds — reflexes, power, sensation, and how the leg behaves when the nerve is put on stretch. When those three agree, the picture is convincing. When they do not, treating the picture instead of the patient is how people end up worse after a technically successful procedure.
Expect a consultation here that spends more time on that agreement than on the report.
The things that imitate sciatica
A substantial number of people arriving with a diagnosis of sciatica do not have a nerve-root problem at all.
- Deep gluteal and piriformis-related pain. The sciatic nerve can be irritated well below the spine, deep in the buttock. The tell is pain that is worse after prolonged sitting and with the hip in particular rotated positions, tenderness deep in the buttock itself, and a pain distribution that does not follow a clean nerve territory. Ultrasound can examine this directly, which no spinal MRI can do.
- Sacroiliac joint pain. Refers into the buttock and down the back of the thigh, and is regularly read as sciatica. It is usually pointed at with one finger, low and to one side.
- Gluteal tendon problems. Gluteus medius and minimus tendinopathy produces lateral hip and buttock pain that is frequently labelled as coming from the back.
- Hip joint pathology. Hip arthritis classically produces groin pain, but it refers to the buttock and thigh often enough that a hip examination belongs in every assessment of leg pain.
These are not exotic. They are common, they are treatable, and they are missed because the scan of the spine came back with something on it.
Spinal stenosis — and an honest word about it
Lumbar spinal stenosis is narrowing of the space the nerves travel through, usually from a combination of disc height loss, facet enlargement and thickening of the ligament at the back of the canal. The presentation is characteristic and quite different from a disc herniation:
- Leg pain, heaviness or fatigue that comes on with walking and eases when you stop
- Relief on sitting, or on leaning forward — over a shopping trolley, a bicycle, a kitchen counter
- Walking downhill worse than uphill, because of the position the spine is held in
- Symptoms usually in both legs, and often more heaviness than sharp pain
Here is the honest part. Stenosis is a structural narrowing, and no injection widens a canal. Anyone offering you a biologic that will reverse stenosis is describing something that does not happen. Injections can have a role in settling an inflamed nerve root and buying comfort, and they are worth trying before a decompression in many people, but the goal should be stated accurately before you pay for it. Where symptoms are progressive or function is genuinely limited, the honest recommendation is a surgical opinion — and you will be referred for one rather than sold something adjacent.
What is offered here for radicular pain
Platelet-rich plasma is the primary biologic used, prepared from your own blood on the day and placed under image guidance.
- Caudal epidural injection. The epidural space is entered through the sacral hiatus, at the very bottom of the sacrum and well below the level of the spinal cord. It is a long-established route with a good safety record and it is technically forgiving compared with approaches higher in the spine. This is the treatment for pain that is genuinely coming from an irritated nerve root.
- Piriformis and deep gluteal injection. Performed under direct ultrasound guidance, with the sciatic nerve visualised in real time so the needle stays away from it while the muscle is treated. This is the treatment for the commonest sciatica imitator.
- Sacroiliac and facet injections where the assessment points there instead. Those are described on the PRP for low back pain page.
PRP is not a treatment for nerve compression itself. What it can do is reduce the inflammatory environment around an irritated root, and it does so without the cumulative cost that limits how often corticosteroid can be repeated. Where the priority is bringing severe acute nerve inflammation down quickly, steroid is sometimes the right answer and we will say so.
What is not offered here
- Discectomy or any other spine surgery. Not performed at this practice.
- Intradiscal injections of PRP or anything else.
- Transforaminal nerve root blocks and interlaminar epidurals — those require fluoroscopic or CT guidance and are not performed here.
- Radiofrequency nerve ablation. Not performed here; we will refer you where it is appropriate.
- Any injectable stem cell product sourced from a donor — amniotic, umbilical cord, placental or “exosome” products are not legal for this use in the United States and are not offered here at any price.
Get seen the same day for these
None of the following is an injection problem, and none of it should wait for a scheduled appointment:
- Progressive weakness in a leg, or a foot that has started to drop
- Numbness in the saddle area — the inner thighs, buttocks or genital region
- New difficulty starting or controlling urination, or loss of bowel control
- Severe leg pain following significant trauma
- Back or leg pain with fever, or in anyone with a history of cancer
Cauda equina syndrome is rare, and it is a surgical emergency in which time genuinely matters.
Common questions
Can PRP treat a herniated disc?
Not the herniation itself. PRP is not injected into discs at this practice, and no injection available today puts disc material back where it came from. What PRP can address is the inflamed environment around the irritated nerve root, delivered by caudal epidural injection. That is a different and more modest claim than the one usually made in this space, and it is the accurate one. Most herniations improve over weeks to months regardless; the treatment question is how well you get through that window.
How do I know whether my sciatica is coming from my back or my buttock?
The pattern usually separates them. Nerve-root pain tends to follow a recognisable territory below the knee and comes with numbness, tingling or measurable weakness. Deep gluteal and piriformis pain is worse after prolonged sitting and in particular hip positions, is tender deep in the buttock on direct pressure, and often does not follow a clean nerve distribution. The examination settles it, and ultrasound can look at the deep gluteal structures directly, which an MRI of the spine cannot.
Do you perform epidural injections?
Caudal epidural injections, yes. The epidural space is entered through the sacral hiatus at the base of the sacrum, well below the spinal cord. Transforaminal nerve root blocks and interlaminar epidurals are not performed here, because they require fluoroscopic or CT guidance rather than the image guidance used in this office.
Will an injection fix my spinal stenosis?
No injection widens a narrowed canal, and anyone telling you otherwise is describing something that does not happen. An injection can settle an inflamed nerve root and buy comfort, and that is worth trying in many people before a decompression is considered. But where walking distance is progressively shrinking or there is measurable weakness, the honest recommendation is a surgical opinion, and you will be referred for one.
Should I get an MRI before I come in?
Not necessarily, and not urgently in the absence of red-flag symptoms. Bring whatever imaging you already have, ideally the images themselves rather than the report alone. If a scan is needed after the examination, it will be ordered for a specific question rather than as a starting point. Imaging that is not tied to a question tends to find things that were always there and were never the problem.
How long should I wait before doing something about sciatica?
Severe pain that is stopping you sleeping, working or walking deserves active treatment now rather than a wait-and-see instruction. Progressive weakness, a dropping foot, saddle numbness or any change in bladder or bowel control needs same-day assessment and is not an injection problem at all. Short of that, the usual approach is to treat the pain properly while the natural history works in your favour.
