Rebuilding leg strength after meniscus surgery

I an 76 years old and have been lifting for 5 years. Last November my left knee was scoped to repair a torn meniscus. Between the injury and the surgery I lost a lot of strength in my left quads. Before the injury I was dead lifting 250 and squatting 190. I have lost some range of motion in both extension and flexion since the surgery.
The problem I am having is it has been very difficult to gain quad strength back in the left quads. I am down to squatting 115 and dead lifting 150 and can't seem to make any gains in the left quad. I get stiffness and mild pain in the knee after a work out but it goes away in the days between workouts. I am scheduled to start a series of 3 hyaluronic acid injection to see if it helps with the stiffness and pain.

This is a situation that is probably going to be more a consult kind of thing. As far as general advice, with ROM I would prioritize doing your best to spend as much time as you can using gravity to extend your knee. This means sitting with your leg up and something under your foot with nothing under your knee. For squats and deadlift, keep adding weight slowly to the bar. You may have to decrease the frequency of load increases to once every couple of weeks and drop the load increases down to 2.5 lbs. Also, this is the type of situation where I have found the knee extension machine to be helpful. If your quad is having trouble coming back online, some isolated knee extension work will force you to challenge it directly. It can also be used as a way to passively force you into greater knee flexion ROMs just by sitting on the machine with some weight on it.

Hope this helps!

I pretty much gave up on full extension. I would hang a bag of weights on my knee with my heel on a bench while sitting. I did this several times a day for weeks. The knee would straighten for a short while but would not stay. I also did the isolation on the extension machine. Actually extension on the left is zero but I have about 5 degrees hyperextension on the right, before the surgery they both had 5 degrees hyperextension.

If you are back to 0 degrees then you got what you were going to get back. It sounds like you are on the right track but the rehab is taking longer than expected. I would keep training, going up slowly, and if you have regular access to a knee extension machine continuing to use it to build up your left quad strength after you do your squats and deadlifts.

I think part of the extension issue is the vastus medalis is is basically missing in action and from what I read there is no way to isolate it to work on it. Any suggestions?