Post arthroscopic knee locking

I had an "exploratory" scoping of my left knee on 7-99. While there was no meniscus damage repaired or removed, the doctor "cleaned up" a lot of "junk". Ever since the knee resumed normal size and range of motion, it locks or prevents me from bending normally to take a step. I have to raise the foot off the floor and let the knee "drop" before I can bend the leg. Two doctors have generally said, "Duh?" and PT specialists have said it involves the VM which was cut into. Any others have this trouble and why?