Good luck with it, I snapped my quadriceps tendon 6 weeks ago, operation to reattach went well, but I’m now into week 6 of 12 to 15 of having my leg locked into a straight position,only allowed to bend it in 3 reps of 10 every day to 30 degrees at the moment, moving to 50 degrees in 2 weeks time and then 10 degrees more every week until I get to 90 degrees.
its the worst injury I’ve ever had because of the massive and uncomfortable recovery time, if I had a choice then the knee is the last thing I would damage.