No. 061990sHouston180 patients

Fake surgery

There was a common operation for people with knee osteoarthritis: a camera went into the knee through small holes, and the joint was washed out or worn tissue was cleaned away. Patients said they felt better afterwards.

A research team split 180 patients at random into three groups. Two groups had the real operation. The third group only had small cuts made in the skin of the knee and nothing was done inside, but in the operating room everything was staged as if it were a real operation. For two years, the patients did not know which group they were in.

You first

Your knee hurts and you’re offered this operation. What would you do?

This answer is hypothetical; it is not the same as what you would do in a real lab.

After two years, which group reported less pain and better movement?

Original result

The two real-surgery groups never reported less pain or better movement than the fake-surgery group at any point over two years. The results were published in the New England Journal of Medicine in 2002, and doctors began to question how well this operation works for osteoarthritis.

What we know today

Later trials comparing surgery with sham surgery gave similar results. In 2017, an international expert panel writing in The BMJ made a strong recommendation against this kind of arthroscopic surgery for degenerative knee disease. The study has a limitation too: almost all the patients were men from a single veterans’ hospital.

The surprising part

One year later, the group with the lowest pain score was the fake-surgery group. The difference was not significant, but the knees where nothing was done did not fall behind.

This page is for information only and is not medical advice. Talk to a doctor about decisions on your own health.

Sources

Moseley, J. B., O’Malley, K., Petersen, N. J., et al. (2002). A controlled trial of arthroscopic surgery for osteoarthritis of the knee. New England Journal of Medicine, 347(2), 81–88. doi.org/10.1056/NEJMoa013259
{"Siemieniuk, R. A. C., Harris, I. A., Agoritsas, T., et al. (2017). Arthroscopic surgery for degenerative knee arthritis and meniscal tears"=>"a clinical practice guideline. BMJ, 357, j1982."} doi.org/10.1136/bmj.j1982

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