I fell down two weeks ago. Thud on my knee (and forearm on a commercial fabric seat of a chair that gave me a 4-inch 'carpet' burn but broke the fall. My knee burns all the time since the fall. Bending it makes it burn really bad when wearing pants over it. There's definitely fluid there according to my doc.
She is such a sweetheart, btw. Her name is Raquel Skidmore, M.D. She gives me a hug each time I come to see her. She does acupuncture, too.
Pray for me.