As someone with two fucked knees I've always ascribed to jogging helping to strengthen the joints.
Mine just have a tendency to occasionally slip out of the joints and then they're fucked for a few days. There's exercises you could do like putting your back against a wall and sliding down until you're holding position at a 45 deg angle, which would probably help doing Megan knees.
Megan Knees Dutz.
I would recommend taking glucosamine. If you've got access to a pool, doing squats and other low impact exercises in water will help you slowly work yourself up.
Run backwards
There's a YouTube channel called 'knees over toes guy' who's all about this sort of thing.Strengthening the stabilizer muscles on the inside and outside of the thigh will reinforce your knee's ability to stay in their intended range of motion. Also, in your standing and walking posture, make your butt/rear inner thighs do more of the work. It may take conscious practice sessions, and you may look funny as your learn how to be otherwise relaxed as you change the tilt of your tailbone, center you weight forward or backward of where you're used to, etc. Approach it as if you're learning to walk for the first time, a full reexamination.
A lot of people have overstressed knees because the knees are taking on too much of the burden of the rest of the body being underdeveloped or atrophied from sedentary living. If you train the rest of your body to be there for your knees, you may one day notice they've been serving without complaint for some time.
