Radiofrequency ablation uses heat, delivered through a needle placed under X-ray guidance, to interrupt the small nerves that carry pain signals from a specific spinal joint.
It is one of the few pain procedures that reliably gives months rather than weeks of relief — in the right patient. Identifying that patient is most of the work.
The joints involved
Facet joints are the small paired joints at the back of the spine, one pair at each level, that let the spine bend and twist. Like any joint, they can become arthritic and painful.
Facet pain has a recognisable pattern: worse with leaning backwards or twisting, often worse after standing still for a while, frequently better when sitting or leaning forward on a shopping trolley. It tends to stay in the back and buttock rather than travelling down past the knee.
Each facet joint is supplied by small nerves called medial branches. Those nerves carry sensation only — they do not control muscle or movement — which is what makes them a reasonable target.
Why the diagnostic blocks come first
This is the step patients most often want to skip, and the one that determines whether the procedure works.
Before ablation, the physician numbs the medial branch nerves with local anaesthetic and asks what happened over the next few hours. If the pain largely goes while the anaesthetic is working, the facet joints are very likely the source. If it does not change, they are not, and burning those nerves will achieve nothing.
Most practice guidance recommends this confirmation before proceeding, often twice, because a single block has a meaningful false-positive rate. It is a nuisance — two extra appointments — and it is the reason the success rate of the ablation itself is as good as it is.
Be honest in your reporting, including if the answer is inconvenient. Saying it helped when it did not leads directly to a procedure that will not work.
The procedure
Similar to the diagnostic block, but longer. You lie face down, awake, with the skin numbed. Needles are positioned against the target nerves under fluoroscopy.
Before the heat is applied, the physician usually stimulates through the needle — you may feel a tingle or a small muscle twitch. This confirms the tip is next to the sensory nerve and not somewhere it should not be.
The heating itself takes about ninety seconds per nerve, and several are usually treated. Local anaesthetic goes in first, so what most people describe afterwards is pressure and warmth rather than pain.
Timing of the relief
Unlike a steroid injection, ablation often gets worse before it gets better. A sore, achy back for one to two weeks is common as the treated nerves settle.
The benefit typically appears over two to three weeks and reaches its full extent by about six. Judging the procedure at day five is judging it too early.
When it works, six to twelve months of meaningful relief is the usual range, and some people get longer.
Why it wears off
Because nerves regenerate. The medial branches grow back, and when they do, the signal returns.
That is not a failure of the procedure or a sign anything went wrong. It is inherent to how it works, and it is why ablation can be repeated — typically once the pain has genuinely returned rather than on a fixed schedule.
It also explains why ablation is a management strategy rather than a cure. The arthritis in the joint is unchanged; what has been interrupted is the reporting line. Using the months of relief to build strength and mobility is what tends to make the next cycle better.
What to ask
Did my diagnostic blocks clearly help, and by how much? Which levels are being treated? When should I expect the soreness to settle and the benefit to start? And what should I be doing with the good months?