Some good stuff there from Moose.
Let me just throw out some more stuff and you weed thru it.
Have you tried different shoes or heeled shoes at all?
Hack squats never LOL, when my knees felt great, were horrible and felt like my knee caps were going to fly off and hit the woman on the treadmill.
Trap bar deads with a raised handle so your knee angle is not so deep
Heavy Rack Pulls from varying heights ie: 4"-5"-6" below knees or even some work above the knees.
Do not go overboard here even, if you feel strong at these, until you put some time in strengthening the tendons and ligaments all over the body.
As mentioned above some RDL;'s or SLDL's
I bought a Hack machine 10-15 years ago and ended up using it backwards sine that did not bother my knees at all. Like a hip sled.
Trigger point work on the hams quads and calves, then foam roll.
Make sure your knees are tracking right over top of the foot. None of that torquing (moving the knee out to the side past your foot) from the knee down the shin.
Might be some supplements that you could take and I am sure there are a few guys here, that may chime in on that too!?
All the best and hang in there