The over-reliance on surgery to treat chronic pain should join bloodletting on the list of outdated medical practices, an expert says.

Orthopaedic surgeon Professor Ian Harris said he hoped to raise awareness that surgery was not a silver bullet and was often ineffective in treating musculoskeletal conditions.

Visiting from Australia, where he is a professor at the University of New South Wales, Harris was among those who spoke at the New Zealand Pain Society (NZPS) conference in Dunedin yesterday.

The multi-day conference is taking place in the city for the first time in 10 years and will end tomorrow.

Harris said studies had shown very little evidence for performing surgery on people with chronic pain in areas such as their necks, backs, knees and hips.

Some research showed the power of the placebo effect, as people had been put under anaesthetic without the procedure being carried out.

“Take shoulder pain for example... there’s lots of operations and they’re very commonly done, but the best evidence we have is that those operations are no better than either pretending to do the operation or not doing the operation at all,” Harris said.

Spinal fusions were common for people with back pain, but were probably ineffective and could be expensive and harmful.

However, clinicians and practitioners tended to overestimate the benefits of what they did while underestimating the harms, Harris said.

The post hoc fallacy was an issue - they could assume changes that occurred following an operation occurred because of the operation.

The goal of his talk was to raise awareness of this and get people to question their own practice, Harris said.

Research on the overreliance on surgery was not particularly new, he said.

When asked why the information had not resulted in more change, Harris said it was a common theme throughout medical history.

Woman with backache, massaging her back. Photo / Getty Images

“Doctors used to use bloodletting to treat people with any number of conditions - for 2000 years.

“They strongly believed that this was helpful and it was only when scientific evidence was shown to them that it wasn’t helpful that they started to question it.”

Laypeople tended to see pain as something with a single cause to treat, but this was not the case with chronic pain.

Treatment needed time and a multidisciplinary approach, as it would often continue after the initial physical cause had gone away, due to changes in the way the brain perceived pain.

“Chronic pain is a complex condition that often has many factors contributing to it and the notion that there’s a silver bullet is just not valid,” Harris said.