Sorry hear to hear Woody. You have probably seen some of my posts on my back, I had a full 360 spinal fusion in Jan of '20. I've had issues for a longtime before that but just grinded through it. My leg mass is still pretty good luckily but have lost a lot of strength as my back till hasn't fully healed. I would recommend not loading the spine, so no heavy squatting. I think you should still be able to hold to your mass if you train correctly, you can still get after leg presses, leg extensions, and several hamstrings movements but I would becareful with deadlifts and stiff leg dead lifts. High reps can be great for the legs as well. One thing I'm getting which I know people with back issues that it has greatly helped is a Glute Loop, an IFBB Pro friend of my highly recommended it for me, here's the best one that they recommend which I think should be fine posting it here as I haven't seen any sponsors that carry something similar bcstrength.com "BC Strength Glute Loop" One of my friends that has bulging discs uses this and talks about how it has helped him so much.