Failed back surgery syndrome: persistent pain after spinal surgery

FBSS is a descriptive label used when back or leg pain continues, or new pain appears, after spinal surgery. The authors of a national survey of UK pain clinics describe a specific group of chronic back pain sufferers whose pain persists despite their having undergone anatomically successful lumbosacral spine surgery. In other words, the operation may have done what the surgeon intended, such as relieving pressure on a nerve, yet the pain remains.

The word failed can be upsetting and is widely criticised. The same authors point out that the term does not identify a cause or give clues to appropriate management and that it may leave an impression of imprecision in diagnosis and treatment. Whatever it is called, the pain is real and has identifiable contributing factors that a pain team can work through.

There is no single explanation, and several mechanisms often coexist. The survey paper describes patients as a diverse group with complex and varied causes. Reasons recognised in practice include nerve damage or irritation that was present before surgery and does not recover completely, scar tissue around a nerve root, a recurring or new disc problem at the same or a neighbouring level, joint or muscle pain from the spine that surgery was never designed to treat, and pain sensitisation, in which the nervous system becomes more reactive to pain signals over time.

The paper also reports that FBSS patients have low quality of life and high psychological morbidity and are frequent users of health services. Persistent pain affects sleep, mood, work and relationships, and those effects can in turn amplify pain. Recognising this is not saying the pain is imagined. It is the reason pain services treat the whole person, not only the spine.

The expectations placed on surgery matter too. Surgery for leg pain caused by a trapped nerve tends to help leg pain more than back pain, and fusion or decompression does not guarantee that the back will be pain free. It is worth asking your surgeon, before any operation, what outcome is realistic.

The UK survey lists symptoms that can include back pain, leg pain or both in varying proportions, with weakness and spasm in the limbs, numbness and possibly bladder and bowel difficulties. Pain from damaged nerves is often described as burning, shooting or electric, sometimes with pins and needles, while joint and muscle pain is more typically aching and activity related.

Some changes need urgent assessment. The NHS says to call 999 or go to A&E if you have back pain and pain, tingling, weakness or numbness in both legs, a loss of feeling around your genitals or anus, changes in your bladder or bowels such as difficulty peeing or peeing or pooing yourself, or changes in how your penis or vagina feels during sex. These can be signs of cauda equina syndrome. The NHS also says to ask for an urgent GP appointment or get help from NHS 111 if back pain is severe and starts suddenly or is getting worse quickly, or if you feel hot, cold, shivery or generally unwell, which can occasionally mean infection, including infection after surgery.

The first step is a careful history and examination, usually with your GP, the original surgical team or a musculoskeletal or pain service. The aim is to separate pain that might respond to further surgery, which is a minority, from pain that is best managed with non-surgical treatment. The NHS notes that in many areas you may be able to refer yourself to NHS community musculoskeletal services for help such as physiotherapy without needing a GP referral.

Imaging, usually an MRI scan with attention to scar tissue and nerve roots, may be requested if symptoms have changed or a fresh structural problem is suspected, though images often show changes that do not explain the pain, so results are interpreted with care. Nerve tests or diagnostic injections are sometimes used to locate the source of pain.

The survey found that pain specialists in the UK identify and handle patients with FBSS as a separate clinical entity and that treatment is often initiated when patients report a level of pain between 3 and 5 on a 10-point scale, using a range of therapeutic options to address the range of presenting symptoms.

Treatment is usually multidisciplinary and built around function rather than a pain score alone. The NHS lists, for back pain that is severe or not getting better, painkillers, group exercise sessions and physiotherapy, manual therapy, cognitive behavioural therapy to help you cope with the pain, and, for long-term lower back pain, a procedure to seal off some of the nerves in the back so they stop sending pain signals. The NHS also says that surgery may be an option if the pain is caused by a medical condition like a slipped disc and other treatments have not helped.

NICE has produced a guideline on low back pain and sciatica in over 16s (NG59) that covers physical, psychological, pharmacological and surgical treatments, and, separately, technology appraisal TA159 on spinal cord stimulation for chronic pain of neuropathic or ischaemic origin in adults. Spinal cord stimulation uses a small implanted device that delivers electrical pulses to the spinal cord. Whether it is appropriate for you is decided by a specialist pain team.

Neuropathic pain medicines such as certain antidepressants and anticonvulsants are often used for nerve-related pain, with the prescriber monitoring benefit and side effects. Painkillers need careful review, because strong opioids generally provide limited long-term benefit for persistent pain and carry significant risks. Do not change prescribed medicines without advice.

Self-management is an essential part of care. The NHS advises staying active and continuing daily activities as far as possible, avoiding long periods of bed rest, and using heat or ice packs for comfort. Walking, swimming, yoga and pilates are mentioned as activities that may help ease back pain, and it advises stopping exercises that make the pain worse and seeing a GP for advice.

Pacing activities, building up gradually, sleep routines and talking therapies can help. Persistent pain commonly affects mood, so tell your GP if you feel low or hopeless. Pain management programmes run by NHS services combine education, graded activity and psychological approaches and are often worth considering. Pain Concern is a UK charity that brings the pain community together and provides information.

On the NHS, care is usually coordinated through your GP, a community musculoskeletal service, a hospital pain clinic and, where relevant, the spinal surgeon. Waiting times for pain clinics vary by area.

Some people seek a private spinal or pain consultant for a second opinion or quicker appointments. Whichever route you use, it helps to bring your operation note, scan reports and a list of previous treatments, and to ask what the realistic goals are. Be cautious of any promise of a cure, and ask for a clear explanation of risks, evidence and costs before agreeing to repeat surgery or a device.