New Delhi : The benefits of injections used to treat knee pain in persons suffering from osteoarthritis are clinically insignificant, a group of leading orthopaedic specialists from across the world has concluded. The specialists claim that the injections are as good as placebo and that if these are administered in excess, there is also risk of adverse events.

Knee osteoarthritis is a chronic disease that involves inflammation and structural changes of the joints, resulting in joint pain and limitations to physical movement. It is a leading cause of disability among older people and an estimated 560 million people are living with the condition globally.

Viscosupplementation, the procedure in which a thick fluid called hyaluronate is injected into the knee joint, has been used to treat knee osteoarthritis since the 1970s, but its effectiveness and safety have been questioned for some time.

According to a study published recently in the British Medical Journal (BMJ), an international team of researchers set out to review existing studies on the subject carried out during the past 50 years to evaluate just how effective and safe viscosupplementation is for pain and function in patients with knee osteoarthritis.

They identified 169 trials involving 21,163 patients with knee osteoarthritis that compared viscosupplementation with placebo (dummy) treatment or no treatment.

“The main analysis of this review, which included a subset of 24 large trials of higher methodological quality involving 8,997 randomised patients, found that viscosupplementation was associated with a small reduction in pain compared with placebo, but the difference was tiny and was described as ‘clinically irrelevant’,” a press statement issued by the BMJ says. It adds: “Their analysis showed that since 2009, there has been conclusive evidence that viscosupplementation and placebo treatment have led to the same clinical result in terms of pain reduction, meaning there is no point to having the injections.”

The research also found from 15 large trials on 6,462 randomised participants that viscosupplementation was linked to a 49% higher risk of serious adverse events than placebo.

Journal Reference: “Viscosupplementation for knee osteoarthritis: systematic review and meta-analysis”BMJ 2022378 doi: