Hi iv had increasing pain in my knee over the past few months and a few weeks ago I turned over in bed and felt my knee cap slip and felt something snap the pain intensified and I was unable to bend or straighten my knee it also sometimes locks clicks and gives way and feels quite tight all around my knee i also have a small painless pea sized lump on my knee cap what I can move about iv ad an mri scan but my results won t be available for a few weeks yet have you any ideas as to what the problem may be many thanks