Ongoing pain after spinal surgery is a recognised problem, and it does not mean you did anything wrong. Doctors now call it persistent spinal pain syndrome type 2 (PSPS-T2). Many patients still know it as failed back surgery syndrome (FBSS). Both terms describe back pain, leg pain or both that continues after an operation on the spine. It can often be helped, but the answer is rarely another operation. A careful review of why the pain persists comes first, followed by rehabilitation, nerve treatments and, for selected people, spinal cord stimulation.
What is persistent spinal pain syndrome?
The older name, failed back surgery syndrome, can be misleading. An operation may have done exactly what the surgeon intended, for example by taking pressure off a nerve, and yet pain continues for other reasons. Persistent spinal pain syndrome is a more accurate description because it focuses on the pain rather than judging the surgery.
It affects people after many kinds of spinal operation, including discectomy, decompression for stenosis and spinal fusion. The pain may be in the back, the leg, or both. Leg pain often has a burning, electric or tingling quality that points to nerve involvement.
Why does pain continue after spinal surgery?
There is rarely one reason. Common contributors include:
- Scar tissue. Fibrous tissue can form around a nerve root after surgery and make it sensitive.
- Nerve injury. The nerve may have been damaged by long-standing compression before the operation, or irritated during it.
- A recurrent or residual disc problem. Disc material can herniated disc again, or a fragment may have been left.
- Changes above or below the operated level. Extra load on neighbouring segments can cause new joint or disc pain.
- Joint or stability problems. A fusion that has not fully healed, or hardware that is irritating, can cause pain.
- A different pain source. Facet or sacroiliac joint pain may have been present all along and was not treated by the operation.
- A sensitised nervous system. Long-term pain can change how pain signals are processed, so that the pain continues even when the original trigger has settled.
- Sleep, mood and stress. These do not cause the pain, but they change how strongly it is felt and how well you can recover.
How we assess pain after spinal surgery
The first question is whether something can still be corrected. Dr Poply reviews your operation note, your scans and your history, examines you, and asks about the exact pattern of pain, including how it compares with the pain you had before the operation. Where a structural problem might be treatable, she will discuss this with your spinal surgeon before recommending anything else.
Diagnostic injections may help identify whether facet joints, sacroiliac joints or a specific nerve root are responsible. We also look at sleep, mood, activity levels and your goals. NICE guidance says spinal cord stimulation should be provided only after assessment by a multidisciplinary team experienced in chronic pain and in the use of the device, and we work in that way.
Treatment options
Rehabilitation and pain psychology
Gradual, guided activity and pacing rebuild confidence and function. Psychological approaches such as CBT or acceptance and commitment therapy help many people live better with persistent pain, and they improve the results of other treatments. This is offered alongside medical treatment, not instead of it.
Medicines
NICE advises against opioids for chronic low back pain and chronic sciatica. For nerve-type pain, a specialist may consider other medicines and monitor whether they are worth continuing. If you are taking several medicines with limited benefit, a structured review can simplify your regime.
Injections and radiofrequency treatment
Where a joint or a specific nerve is identified as a pain source, nerve root blocks, medial branch blocks, sacroiliac joint injections and radiofrequency treatment can be used. These are more useful for particular pain patterns than for widespread pain.
Repeat surgery
Repeat surgery is worth considering when imaging shows a clear, correctable problem that matches your symptoms. When there is no clear surgical target, the chance of benefit is lower. In a randomised trial published in Neurosurgery in 2005, people considered for repeat lumbar surgery were randomised either to reoperation or to spinal cord stimulation. The stimulation group was more likely to report significant pain relief, and many people in the reoperation group later chose to cross over to stimulation. That was a single, relatively small trial, but it is one reason stimulation is discussed before a second operation in selected patients.
Spinal cord stimulation
Spinal cord stimulation uses thin leads placed in the epidural space beside the spinal cord, connected to a small generator implanted under the skin. It sends mild electrical pulses that change how pain signals travel to the brain. The best-documented benefit is for leg pain of nerve origin after back surgery. Newer stimulation patterns that do not produce tingling, such as high-frequency and high-dose programmes, have also been studied for back-dominant pain, and we go through the evidence for your particular pain pattern.
Treatment is staged. First a trial: temporary leads are placed, and over the following days you test the stimulation in daily life. If you get a worthwhile benefit, a permanent system can be implanted. If not, the leads are removed and nothing further is fitted. After implantation you are followed up, and the device is programmed and adjusted with the specialist team.
Dorsal root ganglion stimulation
Where pain is concentrated in one area, such as the foot, groin or a specific part of the leg, the lead can be placed over the dorsal root ganglion serving that region. This is used for focal pain and for complex regional pain syndrome.
Risks and realistic expectations
The PROCESS trial found that 48% of people with spinal cord stimulation reached at least 50% leg pain relief at six months, against 9% with medical management alone, and 37% versus 2% at 24 months. These figures come from patients who were carefully selected, and most stimulator trials are supported by manufacturers, so results in everyday practice may differ. Complete pain relief is not the usual aim. The goal is a meaningful reduction in pain, better function, and often less reliance on medicines.
In that trial, about a third of people with stimulators had a device-related complication, most often lead migration. Other risks include infection, pain at the generator site, lead fracture, and, rarely, nerve injury or bleeding. Some problems need a minor revision procedure. Stimulators can be switched off or removed. If you may need MRI scans in future, tell us, because MRI compatibility depends on the specific device.
About your specialist
Dr Kavita Poply is a Consultant in Pain Medicine and Neuromodulation at St Bartholomew’s Hospital, London. She has taken part in research on how spinal cord stimulation works, including the DIFY SCS-PET study, a double-blind trial that used brain imaging to study responses to different stimulation frequencies, and the HIDENS study of high-dose stimulation for lumbar radiculopathy. She is Programme Lead for the postgraduate certificate in Neuromodulation and Pain Management at Queen Mary University of London.
Frequently asked questions
Q.1 What is failed back surgery syndrome?
Ans. Failed back surgery syndrome (FBSS), now more accurately called persistent spinal pain syndrome type 2, describes back pain with or without leg pain that continues after spinal surgery. It does not necessarily mean the operation was performed badly. Pain can persist because of scar tissue, nerve injury, problems at neighbouring levels, or a nervous system that has become sensitised.
Q.2 Can spinal cord stimulation help pain after back surgery?
Ans. It can help selected people, particularly those whose main problem is nerve-type leg pain. In the PROCESS randomised trial, 48% of those with stimulation had at least 50% leg pain relief at six months, compared with 9% on medical management alone. It is not suitable for everyone, so assessment and a trial period come first.
Q.3 Is another operation the answer if my pain continues?
Ans. Only when scans and examination show a clear structural problem that matches your symptoms and can be corrected. Without a clear surgical target, the chance of benefit from repeat surgery is lower, and other approaches such as rehabilitation, nerve treatments or spinal cord stimulation may be more appropriate. Your spinal surgeon should be part of that decision.
Q.4 How long should pain take to settle after spinal surgery, and when should I worry?
Ans. Recovery takes weeks to months, and some soreness is expected. If pain is new, sharply worse, or comes with fever, wound problems, new weakness or bladder or bowel changes, contact your surgical team or seek emergency help. Pain that continues beyond about three months and is limiting your life is worth discussing with a pain specialist.
Q.5 What is the trial period for a spinal cord stimulator?
Ans. Before any permanent device is implanted, temporary leads are connected to an external stimulator for a short period, usually several days to a couple of weeks. You use it in daily life and record how your pain, sleep and activity change. If the benefit is worthwhile, a permanent system can be discussed. If not, the leads are removed.