Spinemathema podcast · Episode 2 · About 8 minutes · 6 October 2026

Episodes are narrated using an AI model of Mr Sadek’s own voice, from scripts he has written and approved.

Read the full article with references: Surgery or Waiting for a Slipped Disc? The SPORT Trial

Transcript

Hello and welcome to the Spinemathema podcast. I’m Ahmed Sadek, a neurosurgeon, and this is a Research Spotlight, where I take one important study and go through it in plain English.

Today’s study is one of the best known trials in spinal surgery. It’s called SPORT, which stands for the Spine Patient Outcomes Research Trial. It was published in the Journal of the American Medical Association in two thousand and six, and it asked a question I’m asked in clinic almost every week. If I have a slipped disc and sciatica, should I have an operation, or should I wait and let it settle?

Let me start with a quick reminder of the problem. The discs in your lower back sit between the bones of the spine, a bit like cushions. Sometimes part of a disc bulges or ruptures and presses on a nerve. That can cause sciatica, which is pain, tingling or numbness running down the leg. The good news is that many people get better on their own. But some don’t, and for them an operation called a discectomy, where we remove the piece of disc pressing on the nerve, is an option.

So why did SPORT matter? At the time, discectomy was the most common operation in the United States for back and leg symptoms. But the authors pointed out some uncomfortable facts. Slipped discs often show up on scans in people with no symptoms at all. They can shrink without surgery. And operation rates varied up to fifteen fold between different regions of the United States. That kind of variation suggests that doctors weren’t sure who really needed surgery.

Here’s how the trial worked. Between two thousand and two thousand and four, thirteen spine centres across eleven American states recruited adults with leg pain from a slipped disc. The disc had to be confirmed on a scan, the nerve had to show signs of irritation when examined, and the symptoms had to have lasted at least six weeks despite some non surgical treatment. People with emergency problems, such as cauda equina syndrome, were not included.

Five hundred and one people agreed to be randomised. That means a computer decided their treatment, rather than the patient or the doctor. Two hundred and forty five were assigned to surgery, a standard open discectomy. Two hundred and fifty six were assigned to non surgical care. That was tailored to each person, but the protocol recommended at least physiotherapy, advice with home exercises, and anti inflammatory medicines if they suited the patient. Many also had injections.

Everyone was then followed up at six weeks, three months, six months, one year and two years. The main measures were questionnaires about pain, physical function and disability.

Now, here’s the twist that makes SPORT so interesting. A lot of people didn’t stick to the treatment they were given. Only half of those assigned to surgery had their operation within three months. Meanwhile, nearly a third of those assigned to non surgical care had surgery in the same period. By two years, sixty percent of the surgery group had had an operation, and so had forty five percent of the non surgical group.

That’s a huge amount of switching. And it wasn’t random. People who switched to surgery tended to have worse pain and disability at the start. People who turned down surgery tended to have milder symptoms and felt they were already getting better. Which, if you think about it, is exactly what you’d expect real patients to do.

So what did the trial find? When people were compared in the groups they were originally assigned to, both groups improved a great deal. To give you a sense of it, the disability score, which runs from nought to one hundred, fell by about thirty one points in the surgery group and about twenty nine points in the non surgical group at two years. The surgery group did slightly better on every measure, at every time point. But for the three main measures, the differences were small and not statistically significant.

Where surgery did stand out was leg pain. On a measure of how bothersome the sciatica was, the surgery group improved more at three months, one year and two years, and that difference was statistically significant. People in the surgery group also rated their own improvement slightly higher.

The researchers also did a second analysis, comparing people by the treatment they actually received rather than the one they were assigned. That showed much bigger benefits for surgery. But I want to be honest about this. Once people choose their own treatment, you lose the fairness that randomisation gives you. The researchers adjusted for differences between the groups, but they couldn’t rule out that those differences affected the result.

What about safety? Complications were uncommon. There were no deaths around the time of surgery. The most common problem during the operation was a small tear in the lining around the nerves, in about four percent of patients. Ninety five percent had no complications after surgery. About four percent needed another operation within a year, more than half of those for the disc slipping again at the same level. And nobody in either group developed cauda equina syndrome.

So what are the limitations? The big one is the crossover. With so many people switching in both directions, the two groups end up mixed together. That tends to hide any real difference. The authors themselves said you can’t draw firm conclusions about which treatment is better from that main analysis alone. There was also no blinding, so patients knew which treatment they had. Only a quarter of eligible people agreed to take part. And the non surgical care varied from person to person, so we can’t compare surgery with any one specific treatment.

The SPORT team kept following these patients. At eight years, the picture was much the same. Crossover was still high, the main differences were still small, and people in both groups had held on to their improvement.

So what does this mean for you? If you have a slipped disc and sciatica, and no emergency signs, I find SPORT quite reassuring. Most people get a lot better, whichever route they take. Surgery tends to relieve leg pain faster and more fully. Good non surgical care lets many people avoid an operation altogether. Neither choice is wrong.

That’s why I see this as a shared decision. We talk about how bad your pain is, how long it has gone on, how it’s affecting your work and your life, and how you feel about the risks of an operation. And then we decide together.

One important safety point before I finish. If you ever develop numbness around your bottom or genitals, new trouble controlling your bladder or bowels, or leg weakness that’s getting rapidly worse, please seek urgent medical help. Those can be signs of cauda equina syndrome, which needs emergency assessment.

Thank you for listening. Please remember that this podcast is general information and not personal medical advice. If you’d like to read the full article, see the diagrams and check the references, you’ll find it all at spinemathema dot com.

This podcast is general information and is not a substitute for advice about your own situation. Please speak to your GP or specialist.