I've had some pretty bad quadriceps tendonitis the last three weeks or so (tendon above the kneecap).
I saw an Instagram ad selling squat wedges which claimed to help alleviate knee pain. I found a foam one at my gym and gave it a try.
Verdict: Much reduced knee pain! This is the first time I've hack squatted in almost a month. Will continue to play around with it. There is still some pain but much less pronounced. Give it a a try!