After an acl knee surgery would the knee be the same as before (good) if not.. why? thanks

Yes: After a successful acl repair followed by physical therapy and rehab your knee should be quite normal. This is true only if there is no other damage to the internal mechanism of the knee.

See below: Alot of people do very well after an acl repair. If you don't have meniscal tear, cartilage damage, tear of ther ligament and the surgery went perfect, chance of return to normality is high. Be careful not to injure it again. If the patellar tendon is used as an acl graft, degeneration of the patellar cartilage may occur so be careful with it and do well with physical therapy.