Ouch; I hear they're painful.
Hope you recover quickly.
Only to begin with. They get the person up walking within a few days. The bit they replace is then stronger than the old bit. And they do it with glue.
................................
My missus had a knee replacement. 6 weeks and she was back to normal, talking non stop and still always taking ages to actually get out the house.
Seriously though, if you do the exercises and all that, 6 weeks or less and you'll be back working. Maybe you'll be working a bit slower to begin with but without the pain. Your life is about to change for the better come April.
I cannot stress how important it is to do not only the exercises given but any stretching exercises to strengthen those muscles and joints that were affected by the effects of having a painfull knee which throws the whole body out of kilter.