Exercises for Meniscus tear recovery question

[geepondy]

I'm a very active 60 year old who runs and bikes a lot and lifts enough weights to hopefully at least maintain what muscle I have. Earlier this summer I tore my left knee Medial meniscus in essence by over running. As meniscus tears go, I did not think it was that bad with not really any range of motion loss and no locking up, etc. Mostly just a sore knee in general with localized pain in the lower inner part of knee where tibia meets fibular. According to doctors, xrays show the knees to still have pretty good structure. They recommend rest and time as treatment. Anyhow, three months in, and it is extremely reluctant to get better with the knee pain symptoms still vacillating considerably thruout the day and going back to running anytime soon completely out of the question though I can bike a little. I still can't really walk any distance without discomfort.

I have been trying to do some knee rehabilitation exercises with YouTube being my friend. Most say concentrate on the glutes, so that is what I have been doing. Typically I do bridges and variations of such, along with not sure what it is called but being on your hands and knees and extending opposite legs and arms. At the gym, I do hip inner and out abductor machines as that doesn't seem to bother the knee but stay away from the quad and hamstring machines. My question is, some sites say stay away from quad exercises completely while the meniscus heals as strong quads press harder against the meniscus. I imagine I may have a quad to hamstring muscle imbalance as suggested by many sites but should I really ignore the quads completely? When I attempt to do one leg bridges, my good right leg is pretty stable but the left leg with injured knee is much more wobbly and shaky and suggests the whole muscle structure is weak.

Would appreciate any other thoughts or exercise advice particularly if somebody has gone through this. This has been my worst injury since rupturing my Achille's tendon decades ago and it's disheartening to see meaningful lack of progress three months in. Yes, it's better than the first few weeks but I don't feel like I've turned any corners.