Washington: A powerful injection delivered directly into arthritic joints could cut pain levels for millions of sufferers.
Scientists have found a way to stop nerve cells in diseased joints sensing pain - without any side effects.
They say their discovery could drastically cut the number of knee and hip replacements performed in Britain each year - currently around 160,000, and costing the NHS almost 200 million pounds.
Scientists from the Arthritis Research UK Pain Centre at Nottingham University targeted a nerve cell pain receptor called TRPV1.
Previous trials on osteoarthritis patients showed their pain could be cut by blocking the receptor using drugs called TRPV1 antagonists. But the patients experienced the side effect of hyperthermia - overheating of the body - apparently in their digestive organs.
Neuroscience lecturer Dr Sara Kelly explained that the Nottingham team used a model of osteoarthritis pain to see if using the drugs within the joint itself would work better.
Dr Kelly said that by targeting the joint directly they did not see the side effect of hyperthermia.
The study is published in the journal Annals Of The Rheumatic Diseases.