This is what happened to my knees almost every time I did deadlifts (especially with heavy weight):
but thanks to Lisa~ (who suggested reading an article by Mark Riptpeoe "
Analysis of the Deadlift") I found my mistake. It was the position of scapular in relationship to the bar.
My scapulae were behind the bar, rather than directly over it. It made all the difference in the world! I was ready to give up on this great exercise, thinking with my long legs I was not made to deadlift

. But today I even went up further in load - 145 lbs (I weigh 141 lbs) !
Thank you, Lisa~ ! This is a great place.....