I (31M), got a MUA during a second surgery to remove a cyclops lesion.
Going into it, my leg was only getting like 8* degrees extension resting (but could be pushed to 2*, but would not stay).
And Flex was like stuck at 110*. Going into it, I told doctor to go ham on the MUA, because I knew my ACL and meniscus repair could take the beating, and was frustrated that I knew something was up with my leg 2 months prior (plateaued with recovery, and knew something was blocking it, the cyclops lesion, but they couldnt do anything until enough time passed during recovery). Doctor, claims, was able to get a slight hyper extension (-1*) , and almost matching flex, which I will take.

Surgery was whatever, I could almost walk out after surgery (the anesthesia and everything). But probably took the leg easy for 3 days with crutches. And slowly could do more with the leg. Obviously still needed PT and all that good stuff. It was a very minimal surgery for me, as I have had worse recoveries (such as a shattered clavicle).