@wberry - Yikes! Glad you weren't hurt too badly!
From what I've read, it really doesn't matter how much quad strength you had prior to the procedure; I've read two articles that state that the surgery itself-- the way they cut to get to the knee -- causes extreme trauma to the quad muscle. I'm not a medical professional but that makes sense to me because nearly everyone who's had this procedure reports the same thing: an inability to move their leg at all the first 2-3 weeks post-op, and then - voila! -- one day, out of the clear blue, it responds on its own. I'm 8 weeks post-op and still occasionally stumble because that quad muscle is a little lazy and doesn't always wake up when I need it; sometimes there's a little lag. Luckily I don't go anywhere without my cane and it has so far, kept me from falling.
Re the wobbling: In those first few weeks when I was still on the walker, my in-home PT gave me two suggestions that you might find helpful. As with all advice, as a friend of mine used to say, "take what you need and leave the rest behind":
1. The walker is meant to steady yourself, not really to be weight- bearing. It's too lightweight for that. Try to hold yourself as upright as possible when using it; avoid leaning forward OVER the walker too much if you can.
2. My PT had me do a weight-shifting exercise that helped with my wobbling. While holding onto the walker or a sturdy piece of furniture, shift your weight slowly from one leg to the other. Don't move your feet. Just stand as straight as you can and shift your weight from one foot slowly. ..to the other. Felt weird at first but it was really helpful for me to get used to letting my new knee carry some of my weight.
Additionally what has helped me in more recent weeks was to avoid gripping the cane in a stranglehold. You are probably not there yet, but at 8 weeks, now that I have a little more strength, I am learning to trust my legs and make them work a little and use the cane for steadiness, not to lean on.