Post ACL Surgery and HGH

I am getting ready to have ACL surgery. Because of my job and constantly being on my knees (lol !) I have opted for use of a cadaver ligament. Doc says patella graft can cause pain if I put my knee on the ground.

Anyone have any pointers on using HGH for the rehab process. When to start, how much to take, where to inject, etc.

All tips welcome.