Andrew Lansley 'wrong about knee operations' It's a question of working out what the criteria are, not restricting things that are clinically desirable. But Prof Dias, a consultant orthopaedic surgeon in Leicester, responded: "This is factually wrong. For a start, there's no data about all of knee surgery. He said the NHS evidence was clear that total knee replacements did provide significant patient benefit. Patient reported outcomes measures, known as Proms, showed that those reporting pain in the knee in question was reduced from 38 per cent before the operation to six per cent six months afterwards, he said. Those reporting no mobility problems in the knee was raised from six per cent before to 47 per cent afterwards, he added. He said another Proms measure looking at wider aspects of a person's health after knee surgery did show more limited benefit - but that a knee operation could not be expected to improve a person's overall health. He commented: "Our concern is that patients will read this and think, 'Why am I going to have surgery if there's only a 50 per cent chance of being improved?' " He believed Mr Lansley had been misinformed by the Department of Health. Orthopaedic surgeons have become increasingly concerned over the last year at hip and knee operations being put on lists of treatment of so-called 'low clinical value'. Some appear to have tried to reduce demand for them by selectively quoting the least impressive statistics. A spokesman for the Department of Health emphasised that Mr Lansley was not doing down knee surgery. She said: "Data from the NHS shows that only half of patients report any improvement in their health after a knee operation. However, as the Secretary of State made clear in the interview, it should be for doctors and patients to make the decision as to whether having a knee operation is appropriate.