Absolutely!
My better half's aunt had ACL reconstruction in the D.R. She was instructed NOT to remove the knee immobilizer for one month, then to start therapy afterwards.
I had right leg ACL reconstruction at the Texas Medical Center in Houston... woke up in my room a few hours later, with my leg strapped to a continuous passive motion (CPM) machine, which flexed and extended my leg fully every 44 seconds. Discharged the next day with instructions to replicate same movement on the floor as soon as I arrived home, and to commence therapy as soon as possible. ACL tear on left leg 5 years later. No machine, but I already knew what to do. "NO problemo."
Her aunt's still limping and unable to fully extend her leg... a year later, y con dolor diario.