Hi Jellyfingers ,don’t worry to much about the 90 degree bend,it takes awhile for it to improve ,gentle flex exercises will work .I measured mine today and it’s now 20-25 degrees more than when I left hospital and I have only stuck to the exercises that are simple and not pushed it too far .In the early stages I was well aware how stiff everything was ,not the joint really,it was the poor traumatised muscles and tendons .To give you an idea of how much things can change ,after the op if I lay on my back I could draw my non op leg back a long was but hardly move my op knee back ,now they aren’t that far apart and I really didn’t do anything aggressive at all ,I overdid it once and boy was it painful,so never again .Sorry to jabber on but hope it helps .
United Kingdom