One of western medicine’s most common surgeries may actually be unnecessary, a new study has found. Currently, nearly 21,000 subacromial decompression surgeries take place annually in the UK. In the US, that number is more like 200,000.

Researchers at the University of Helsinki have spent the last two years comparing the results of patients who actually underwent the surgery with those of patients who had a placebo surgery and found that the surgery might actually provide very little benefit.

The study, which was published in The BMJ, details the findings of the Finnish Shoulder Impingement Arthroscopy Controlled Trial. The trial involved 189 patients that had complained of chronic shoulder pain for three months or longer. Many of the patients had previously received steroid injections, physiotherapy and conservative treatment.

After looking into the patient’s past experiences with shoulder pain, scientists placed them in one of three groups: those receiving subacromial decompression surgery, those receiving placebo surgery through diagnostic arthroscopy and those receiving supervised exercise therapy.

The patients were checked up on two years later and asked about their pain levels. Although pain levels improved drastically in all three groups, the group that received placebo surgery had improved almost as much as the group that received subacromial decompression surgery.

The exercise therapy group also improved, to the point where they were nearly as improved as the group that received decompression surgery.

With the evidence gathered by the trial, the future of medicine in this field may begin to lean away from surgery and toward non-invasive methods of pain remediation, says researcher Teppo Järvinen.