A simple jab could be the first treatment to halt the progression of osteoarthritis.Early studies suggest this new drug, a form of antibody, tackles the disease itself rather than the symptoms alone.Osteoarthritis, the most common type of arthritis in the UK, is responsible for more than one million GP consultations a year.It occurs when the cartilage that lines and cushions joints becomes rougher and thinner, usually as a result of wear and tear.The bone tries to compensate by thickening and creating growths or spurs that can make the joint stiff and inflamed.The knees are one of the most commonly affected joints - one in five adults over 45 has osteoarthritic knee pain.Painkillers or physiotherapy can only help control symptoms but will not stop the damage getting worse. Microfracture surgery - using a drill or pick to make holes in the bone surfaces to encourage new cartilage to grow - can help, but in more severe cases the only realistic treatment option is to have an artificial joint replacement.The new injection, based on antibodies from the immune system, acts on one of the key players of the condition, a compound called Interleukin-1 or IL-1. This is a cytokine - a chemical messenger for the immune system. It also has a role in inflammationIt is thought that IL-1 gathers around joints after knocks or as a result of day-to-day damage, causing inflammation and harm to the cartilage - so it may have a crucial role in the development of osteoarthritis.It has also been suggested that IL-1 is also involved in increasing the perception of pain.The new drug, known as ABT-981, is an antibody that blocks the activity of the harmful cytokine and is injected into the joint area. Early animal tests have found that it can stop the disease getting worse.Having passed initial safety checks, the drug will be tested in U.S. trials in Chicago, Sacramento and Honolulu on people with osteoarthritis of the knee. The study involves 320 patients who will have three doses of the drug or a placebo, and the results will be compared after 12 months.The treatment may be suitable for other forms of arthritis, as the cytokine is found throughout the body.Jane Tadman, of the medical research charity Arthritis Research UK, welcomed the study. 'Blocking IL-1 is known to be a successful approach in the treatment of autoimmune diseases such as rheumatoid arthritis,' she says.'However, there has also been interest in IL-1 as a therapy for osteoarthritis, as this molecule is known to be active in osteoarthritic joints.'Current drug treatments for knee osteoarthritis are limited in that they have significant side-effects and are not suitable for many people. There is an urgent need to find new and better ways of managing their pain.'Meanwhile a new knee-warmer treatment could help combat the pain of arthritis.A needle is inserted into the joint to deliver radiofrequency - radio waves that produce heat.Normally the inside of the knee is 35c; this tiny probe heats it to 42c for ten minutes. It's thought this helps interfere with the pain signals being sent from the knee.A hundred people who have had knee pain as a result of osteoarthritis for at least three months are taking part in a trial of the device at Cukurova University in Turkey. Their pain and mobility will be assessed one, four and 12 weeks afterwards.This follows smaller studies that have shown the therapy to be effective. In one reported case at the Institute for Anaesthesiology in Switzerland, a patient who'd had long-term knee pain experienced ten months' complete pain relief following the treatment..