Abraham Lucas is from my "hometown" Everett, Wa, so I have been hoping for him to have a successful career.
He has been playing at a high level here in Washington State for a long time. This can take a toll on the body and sometimes that "toll" is "inflammation" in an otherwise healthy joint. There is a condition called "Bursitis" that can come from chronic (extended time) "over use" of a joint (I am just guessing about this). I have not read about him having any serious "structural" knee problems.
So, maybe the surgery, physical rest and time off that his body has received will have helped him to heal.
Even if he is a little bit "broken"...he is still a powerful player.