Diode laser hair removal on knee (knee has metal staple(s) from ACL surgery). Would you allow laser treatment over this area?

There is no issue with getting laser hair removal on the knee area in your case. The laser only affects the skin and the staples are much deeper. 

I'm confused as to why your treating office doesn't know the answer to this question, and that begs the further question: what else do they not know? Yes, I would allow you to have laser hair removal with this laser. Hair follicles are located in superficial depths nowhere near the depths that staples are and so there is no reason you cannot treat there. "This answer has been solicited without seeing this patient and
cannot be held as true medical advice, but only opinion. Seek in-person
treatment with a trained medical professional for appropriate care."