Hundreds of thousands of people have surgery on their knees. A new study from Finland says many of these people might be wasting their time and money. The surgeons who conducted the study said some knee surgery can make knee problems worse rather than better. The surgeons spent 10 years studying the results of knee operations. They found that surgery on tears in the knee cartilage rarely worked. The doctors said many of the operations were unnecessary. They added that some of the operations they looked at accelerated the rate of cartilage damage. One doctor said: "What has been shown dramatically is that patients who have this procedure have more pain."

In happier knee-related news, doctors from the University of Colorado have discovered a new method to treat chronic knee pain. Dr Leigh Casadaban has performed simple operations on people's knees. Her method involves reducing the flow of blood to pain-causing areas in the knee. Less blood in those areas reduces swelling and pain. Dr Casadaban says her method is more effective than painkilling medicine and physical therapy. She also believes it means people can avoid knee surgery, even total knee replacements. She said her method could "provide years of relief" by reducing pain inside the knee joint. She said 70 per cent of patients have amazing results.