What a facet joint is, and why it hurts

Each vertebra meets the one below it at three points. The disc sits in front. A pair of small synovial (fluid-filled) joints sits behind, one on each side. Those paired joints — the facets, or zygapophysial joints — guide and limit motion. They are true joints, with cartilage, a capsule and a nerve supply. Like any other joint, they can wear, inflame and hurt.

Each facet joint gets its nerve supply from the medial branches of the dorsal rami (small nerves off the back of the spinal nerves). One comes from the level above, and one from the level where the joint sits. The whole diagnosis rests on that double supply. To numb one joint, you have to block two nerves. If blocking those two nerves stops the pain, the joint they serve was the source.

Does facet arthritis show up on an MRI?

Facet arthropathy (facet joint disease) shows on CT and MRI. It also shows in huge numbers of people who have no back pain at all. It becomes far more common with age. So in anyone past their forties, a report of facet degeneration is describing a normal finding for that decade. It is not describing a cause of symptoms.

The reverse is also true and less well known. A facet joint can be a full-blown pain source and still look normal on imaging. That is because an inflamed capsule and a sensitized medial branch do not show up on a scan. So the scan gives false positives in people who do not hurt and false negatives in people who do. That is a fairly complete description of a test that should not be used to make this diagnosis.

What are the symptoms of lumbar facet syndrome?

• Axial rather than radiating — across the low back, often to one side. It sometimes spreads into the buttock or the back of the thigh, but it typically does not go below the knee.
• Worse with extension — standing for a while, walking downhill, reaching up, arching back. The facets bear load when you bend back and are unloaded when you bend forward.
• Worse getting up from a chair or out of a car, and easier once you are moving.
• Morning stiffness that eases within thirty minutes or so, then returns as the day goes on.
• Tender over the joint line a couple of centimeters off the midline, at the level involved.

Every one of those features overlaps with something else. That is not a flaw in the description. It is the reason the clinical picture alone is not enough, and the reason the block exists. The exam narrows the field to a level or two. The block settles it.

How is lumbar facet syndrome diagnosed?

What causes lumbar facet syndrome?

The mechanical account is simple, and incomplete. As a disc loses height, the facets behind it are pushed closer together. They take a larger share of the load than they were designed for. Years of that cause a thickened capsule, cartilage loss and an inflamed, sensitized joint. Holding extension postures and repeated lifting speed it up.

The account that gets left out is what the joint is made of. Facet cartilage and capsule are collagen. In a state of chronic hyperinsulinemia (high insulin over a long time), collagen is glycated and cross-linked. It is stiffer, less able to spread load, and slower to renew. Metabolic inflammation keeps the joint breaking down instead of repairing. So the small damage from an ordinary week does not fully clear before the next week begins. Give two people the same lifting job. The facet joint fails in the one whose tissue could not keep up with the repair debt.

And the third layer belongs on this page, because it is a cause and not a footnote: the schedule. Rotating shifts and short sleep suppress the slow-wave (deep sleep) phase, when most tissue repair happens. And the food available at the end of a late shift is engineered around acellular carbohydrate. That is not a lifestyle aside. It is the reason the tissue was in deficit before the load arrived.

How do you fix lumbar facet syndrome?

If the block confirms the facets, radiofrequency neurotomy interrupts the medial branches, and the joint stops reporting pain. The relief lasts until those nerves regrow. That typically takes many months, and the procedure can be repeated when it does. It changes nothing structural about your spine. That is exactly its advantage over the alternatives.

What the procedure does not do is fix the reason the joint became a pain source. That is what the quiet window is for. Recondition the extensor muscles so the passive structures carry less. Restore your tolerance for extension instead of avoiding it forever. And address the metabolic terrain so collagen renewal is not running at a deficit. A licensed, pain-trained clinician delivers the behavioral part of that here in-house. That is because a program handed over as a referral is a program that does not happen.

Steroid injection into the facet joint is a different and generally weaker option than the medial branch pathway. We will tell you when it is worth doing, instead of defaulting to it.

Orthobiologic treatment options

For a facet joint proven by a block, radiofrequency is still the option that lasts. PRP placed inside the joint is the choice for people who want to try repair first, or who are not ready for a nerve ablation. A 2025 low back guideline from a national pain society rated facet PRP as limited evidence. It still gave it a moderate recommendation. A 2026 review found PRP gave better pain relief than steroid at three and six months in facet and SI joint trials.

The shot is guided by imaging. You stay awake with local numbing, and most people drive home. It is done at our regenerative clinic, 4477 Woodson Rd in St. Louis, and paired with the same strength work this page describes. Groin pain that rides along with facet pain may be the hip joint. See hip arthritis.

Common questions

How do I know it is facet and not disc?

Broadly, facet pain is worse in extension and better in flexion. Disc pain is worse in flexion and sitting, and better standing. Facet pain is axial and stops around the knee. Disc-related nerve root pain runs past it in a defined line. But the overlap is real. That is why the answer comes from a block, not from a description. The disc question, in full.

Will a facet block cure me?

A diagnostic block is a test, not a treatment, and it is short-acting on purpose. Its job is to tell us whether the joint we suspect is the joint that hurts. The lasting treatment is the neurotomy that follows a positive result.

For how the neurotomy is done, read lumbar radiofrequency ablation.

How many injections will I need?

There is no set course. Anyone offering you a package of three has decided the answer before examining you. How many you get is a clinical decision, based on what the previous procedure achieved.

Is radiofrequency ablation permanent?

No, and that is by design. The medial branches regrow. That is why the effect wears off and why the procedure can be repeated. A permanent nerve lesion is a much bigger commitment, with a much longer list of ways to be wrong.

Can facet pain go away on its own?

An acute (new and short-term) facet sprain often does. A joint that has caused pain for months, on a spine that has been shifting load for years, generally does not resolve unless something changes — either the load, the terrain, or the signal.

Is a facet joint injection the same as a medial branch block?

No. A medial branch block places a small amount of local anesthetic, with no steroid, on the two nerves that supply the suspect joint. It is a test that tells us whether that joint is the one that hurts. A steroid injection placed inside the facet joint is a different and generally weaker option. We will tell you when it is worth doing, instead of defaulting to it.

What do I do in the hours after a medial branch block?

You keep a written record, hour by hour, of how much pain you have and what you can do. Not a general impression the next day, an hourly note. That record is the actual test result, and you are the one who collects it. If the block quiets the pain, the joint those nerves serve was the pain generator.

Can exercise help lumbar facet syndrome?

Yes, and it is part of the plan, not an extra. Once a confirmed facet joint has been quieted, the window is used to recondition the back extensor muscles so the joints carry less load. It is also used to rebuild your tolerance for standing and arching back instead of avoiding it forever. The procedure quiets the joint. This work addresses the reason it became a pain generator in the first place.

Do I need a referral to have my facet joints tested?

No. You can book directly; some insurance plans want a referral on file before they cover the blocks, so check yours. The exam comes first, and a block is booked only if the exam points to the facets. How the medial branch block works.

Facet backs usually start with gentle work that avoids arching; our physiotherapy program for back pain shows the treatments and home exercises a physician may order.

Related reading

• The diagnostic block, explained
• Radiofrequency neurotomy
• What your MRI actually showed
• Sacroiliac joint pain
• Back pain doctor in St. Louis
• Orthobiologics for back, spine and hip pain: PRP, bone marrow and fat

A vertebra that has slipped forward changes which structures carry the load.