Hi Ray, so sorry to hear you are having issues with flexion, and your earlier setback. I would delay on an MUA and work towards controlling your swelling, which is likely behind the problem. Make sure you ice all the way around your knees and use your compression stockings after you ice to keep swelling down. That may help to settle angry tissues which are not very happy at the moment.
The analogy is, you can't bend a hose full of water very easily, so think of your knee as that hose, it really doesn't want to give way. If you keep icing and elevating, and gentle bending, stretching you should see progress, even if it is slow. After some additional weeks, if you are still missing flexion to that degree, then perhaps MUA is in order. If you need one, it's not a bad procedure at all, and for some, the kick start needed to get moving again.
Please keep us posted. I'm sure others will be along with advice as well!
Be well,
Dawn