L2H, why not just warm up thouroughly and then go straight to the heavier weight? I know you said you have been nursing an injury and that does change things a bit, but say you were 100%, would you still do it this way?
For example, this is how I'll do it. I typically do 1-2 sets at 135 10-15 reps and then one set of 225 at 10 reps. After that straight to working sets, usually one at 315 10-15 and then 405-455 for 2 or 3 more 6-12 reps depending on how things are feeling that day...just my thoughts...obviously your legs are doing pretty well.
Well my friend at 44 YO these joints need some warming up

I have always felt the best way to warm up is by doing the excersise (compound types) I like to progressivly add weight and will pyramid pretty much everything.
Typically I will if feeling healthy omitt the set at 275, did that today cause first time squatting in a long while and with being injured wanted to take it slow and see how it felt.
These are ways I will work up depending on how I feel.
barx15, 135x12, 185x10, 225x12, 315x12, 365x12, 405x8-12, 315x15-18
Barx15, 135x12, 185x10, 225x12, 315x12, 405x10-12, 405x10-12
Seldom do I go heavyer than that but if i really feel it i may do 465 I think I have done 8 reps with that. Its really not worth it to me to go that much, the risk of injury becomes too great. I squat raw without knee wraps ever.