If this is anything like "water under the knee" which is what many dancers get after rolling on their knee caps all night, then you need to try to stay on your shin bone instead. When you are on your knees scoot your booty backwards so that your weight is on your shin bone and when you are doing knee moves try to place your weight on your inner knees by spreading your knees wide, tops of your feet or on your hands. (this all depends on what tricks your doing.)
I hope this helps and that you have a speedy recovery. Smiles, Leesi