Knee brace to delay replacement?

What have people’s experiences been of using a knee brace like the Donjoy ones prior to surgery?  Have people found that they help to delay the necessity to have a knee replacement?  It’s a big investment but could potentially be worth it.  I know I am going to need a replacement (and am on the waiting list) but my pain level has been improving in recent months since a suspected ruptured Baker’s Cyst so my most recent discussion with my consultant has led to consideration over the next few months of whether I can get my pain and mobility  to a level I feel is manageable and therefore delay the replacement for a while longer.