that the joint is consistently warm indicates that there is an ongoing inflammation in the joint. there are a number of things that could cause this but the loose fragment is the most obvious one from what i read.

90 degrees after seven months would worry me a small bit but given the Wikipedia reference-linkmri results i believe that there are reasons that may explain your deficit in range. what does it feel like when you try to push past 90, is it a solid "bony" end feel or does it feel "springy" and soft tissue like? again it could possibly be that the loose body is positioned in such a way that its limiting further flexion of the joint. if the joint is hot and swollen that would limit flexion also.

IF its the loose body thats causing most of your problems, and its removed, in theory it should immediately make things a lot easier for you.