I have had 6 ACL replacements (3 on each knee) and numerous menisectomies ... just had my left knee totally replaced ... been lifting for over 35 years ... just want to share what I know from personal experience ...
The suggestion to choose cadaver tendon (vs patellar or hamstring graft from you own leg) is dead on ... recovery is much faster ... if you take graft from your own leg, you are recovering from yet another injury ...
You probably have learned what I'm about to share from your ortho surgeon (if he is any good) but for the record ...
During ACL replacement, they essentially take tissue (the middle third of the patellar or hamstring tendons, either cadaver or your own) and install it in the previous ACL location, anchored by bio-absorbable screws into your tibia and femur. This tissue only provides a structural framework for your body to build scar tissue around to stabilize the knee. In some cases, the new graft does reestablish its own blood supply but not that often. The interesting thing is the patellar or hamstring tendon is structurally much stronger than your original ACL but lacks the integrity necessary to withstand the torsional forces it is designed to absorb. It takes a year for the connective tissues, scarring, and blood supply to get properly established where you can return to all previous activities. You you will be off of crutches in a day or two and can resume most non-ballistic activities in 6 weeks. The movements you must avoid with an ACL replacement are torsional or twisting movement. I blew my last ACL (which had already been replaced twice) reracking a loaded bar after deadlifts ... just twisted the upper body a little while holding the loaded bar and heard it pop. So you need to avoid those types of stresses, which surprisingly you experience every day ... think about how your left knee is torqued when you get in & out of the driver's seat in a car ... see what I'm talking about? Bottom line for your ACL, follow your physical therapist's recommendations, give yourself a break (no big deal if you take a little more time to recover versus reinjury - I have lots of experience with stupid over achieving during PT), know you will lose ~50% of your leg strength just from the surgery but it will quickly return within a few months. You should be able to begin squatting (not monster weights but full squats) in 6 months. Recognize that squatting puts significant stress on the ACL because your upper and lower legs want to go in different directions ... there are many other exercises you can do that won't put the shear force on the ACL that a squat will. Do all the "silly" exercises they give you to stabilize the knee ... the strength of the knee stabilizers is the key to successful recovery ... that is why Adrian Peterson recovered so well ... his leg & knee strength were enough to compensate for the lack of structural integrity in his ACL. But in all cases, I was squatting heavy again within 9 months - of course, always paying the utmost attention to form and gradually building up the leg.
During a menisectomy, they are almost always removing or trimming the torn cartilege, very rarely do they repair by suturing two pieces together. In the long run, the torn cartileges were my undoing ... there was no more cartilege cushioning my left knee, hence knee replacment (at age 54) and now no pain whatsoever in the knee. Even doing both ACL & cartilege in same surgery, you will be off of crutches in a day or two. Full recovery time for the menisectomy is only 6 weeks ... just long enough for the cartilege to heal where it was removed. However, the "gotcha" for cartilege repairs is compression since you it serves as a cushion for the joint. So you really don't want to put any major compression on the joint for the full 6 weeks or you run the risk of irritating or retearing it where it was repaired. Once again, follow the PT advice, do your exercises, take it easy, and it will be in your rear view in no time.
You should be able to do ALL of your upper body work except standing movements ... even with light weight, it would be too easy to reinjure the leg. So there is no reason you cannot maintain your upper body through recovery.
One thing I found as a result of my surgeries (I have also had ankle, shoulder, & back surgery ... lots of extreme sports with accidents!) was my joints and strength actually improved after the surgeries. This was the result of learning new ways to strengthen and stabilize through my physical therapist. I set shoulder & leg PRs AFTER having surgery on those joints. So look at this as an opportunity to learn more, try new movements and regimens, and find ways to work around injury.
With respect to HGH & T, I think they would help accelerate your recovery but in no way to the degree suggested by some in this thread. I don't think you are a professional athlete, just a guy like myself who wants to look & feel good as we invariably get older. It will not make a huge difference in the big picture if you take 3-6 more months to get back to baseline versus the risk of reinjury and the long-term implications on your body as you get older. I had little respect for all the damage I did while younger - I always thought they could cut, reattach, whatever, and I would work out to get back to 100% ... but in the last 10 years, all that earlier foolishness has come back to haunt me ... so be smart ... a few extra months is insignificant in the big picture ...
That's my 3 cents ...
Good luck!
