I think the idea of raising your bad leg is to allow the blood to return more easily to the heart and so improve circulation and relieve inflammation. For years I failed to understand that the injured foot/knee must be HIGHER THAN THE HEART for this to work. This is quite hard to achieve. You can do it partly by raising the foot end of the bed on blocks/books. However this means sleeping head down. I have solved the problem by piling 2 square, ultra firm floor cushions at the foot end of my bed, padded for comfort with ordinary pillows. Thus I am sleeping in a jack-knifed position. You can get the same effect by lying on the floor with your feet raised eg on a sofa. Good luck!