Since movement within reason is the goal, my doctors encouraged whatever position allowed me to move. Keep knee elevated during day while sitting, but keep it flat with body at night. If you are not sleeping, you will not heal. After I weaned off the narcotics (as quickly as possible), I would use Tylenol PM to help on nights when I could not get comfortable. Btw…I weaned off narcotics by getting off during day first…the going down in strength over time at night…1 pill…1/2 pill…1/4 pill, then just tylenol. This worked for my 2 medial knee replacements, my repair of spiral fracture of the fibula and my tibial plateau fracture repair.