A follow-up to my video on why surgery for back pain often doesn’t work, explaining what spinal surgery is genuinely for, and the specific situations where it can help back pain itself.
A couple of years ago I made a video titled “Why Surgery for Back Pain Doesn’t Work.” It reached a large audience and prompted some important questions, which deserve a proper answer. So let me set out what we actually operate for, why back pain itself is such a difficult target, and the scenarios where surgery for back pain can genuinely help.
What spinal surgery is mostly for
Most of the time, certainly in my own practice, spinal surgery exists to treat symptoms arising from trapped nerves, or to protect nerves or the spinal cord that are under threat.
Spinal stenosis. Narrowing of the spine from a combination of disc bulge, thickened ligaments and thickened facet joints, trapping the nerves. The symptom is characteristically not back pain but pain radiating into the legs on standing and walking, shortening your walking distance and easing when you sit down.
Spondylolisthesis or foraminal stenosis. A nerve becomes trapped as it leaves the spine because one bone has slipped slightly forward over the one below, causing leg pain.
Herniated disc. A fragment impinges on a nerve, sending pain shooting down the leg. This is sciatica.
Each of these can be treated with minimally invasive surgery. A microdiscectomy uses a small incision, an operating microscope and a narrow channel into the lower back to shave away the fragment of disc pinching the nerve. For stenosis, we remove some of the thickened tissue compressing the nerves. Both relieve the leg pain with a quick recovery. For a spondylolisthesis causing nerve compression, a metal construct at the back of the spine, screws and rods with a device spacing the vertebral bodies apart to create room where the nerve exits, can be very successful.
Notice what all of these have in common: the problem is clearly defined, and the target is a nerve.
Why back pain itself is different
The difficulty with back pain is that several factors usually contribute at once. We consider this under the umbrella of the biopsychosocial model.
There are biological causes, genuine pathological findings on a scan that really do contribute. But other factors frequently take over later. Mistaken beliefs about what is causing the pain lead to protective behaviours, and those behaviours have been shown to make matters worse. Some contributors never appear on a scan at all; muscle problems, for instance, are largely invisible on MRI unless there is a physical tear.
There is also the matter of over-interpretation. Around twenty years ago, as MRI became widely available and far more people were scanned, there was an explosion in spinal surgery and a great deal of metalwork placed into people’s spines. The results were poor. We have spent the years since learning which findings actually contribute to pain and which are simply incidental.
One study scanned people of different ages who had no back pain at all. Common findings, disc degeneration, dark discs, bulges and protrusions, turned out to be very common throughout that population.
Think of pain as a jigsaw puzzle. A finding on a scan is one piece of it. Over time, other pieces, abnormal beliefs, fear, stress and anxiety, join it, and these have been shown to be potent amplifiers of pain.
This is precisely why a thorough history and examination matter so much, and why the findings must be tied back to the clinical picture.
When surgery for back pain itself can help
There are real mechanical causes of back pain where surgery is appropriate.
Fracture. Whether from trauma, osteoporosis, or occasionally a tumour or infection causing collapse of the bone. If it fails to heal, stabilising the segment with screws, and sometimes cement, can be very helpful.
Spondylolisthesis without nerve entrapment. The slipped segment moving back and forth can cause back pain through mechanical instability alone. Depending on the level, a TLIF (transforaminal interbody fusion) with screws, rods and a cage allows the segment to fuse.
Disc degeneration, in selected cases. This is where it gets difficult. Degeneration is extremely common without symptoms, so deciding whether it is the culprit comes down to a careful history, examination, and a clinician’s experience.
There are tests that help. An MRI may show inflammatory changes in the bone above and below a disc, known as Modic changes, though these too are not especially abnormal on their own. But if a SPECT CT scan then shows uptake of the radioactive tracer at that same segment, matching the MRI, the two together point convincingly to that disc as the source of pain. In that scenario an ALIF (anterior lumbar interbody fusion), approaching from the front of the spine, can be very helpful.
Why this needs a team
Where back pain is the main complaint, clinical assessment and ruling out significant pathology are vital. This is best done with a surgeon, physiotherapist, pain specialist and radiologist working together, so that the true source of pain, and therefore the right treatment, is decided collectively rather than by one person reading one scan.
The key takeaway
Spinal surgery is powerful, but it is precise. It works best when the problem is clearly defined.
Back pain is rarely that straightforward, because several factors contribute at once. That is not a reason to despair of treatment. It is a reason to insist on a proper assessment before anyone reaches for an operation.
