A flexion of 110 degrees allows you to do almost everything you need to do.
At 8 months post-op, you are still only two thirds of the way through this year-long recovery, so you still have plenty of time for improvement. ROM can continue to improve for a year, or even much longer.
Where you are now is not where you're going to end up.
I suggest you and your advisers stop worrying about your Range of Motion (ROM) and take some pressure off yourself and off your knee. Try to forget about the numbers.
Stop doing anything to try and increase your flexion - and that includes using the recumbent bike and trying to take walks of a measured length.
By swelling again so easily, your knee is telling you it doesn't like all the exercising. It needs to be allowed to recover at its own speed, not some one-size-fits-all, artificial schedule.
It's swelling that is stopping your knee from bending more, not arthrofibrosis.
Instead of exercising, spend more time resting, icing and elevating your knee, to try to help it calm down. Don't do any formal exercises, but just use your knee normally, during the course of your activities of daily living - doing that is exercise, too.
You've faithfully followed one course of action and it isn't working for your knee, so you have nothing to lose by trying something different.
Knee recovery - Lose the Work Ethic!!
My surgeon never wants to know ROM numbers. He looks at my knees and says "Show me what you can do." That's because function is more important than the numbers.
A flexion of 110 degrees isn't marvellous, but it's acceptable at 8 months post-op, and there is still time for it to improve.
These are the approximate degrees needed for certain everyday activities:
- 65° to walk properly
- 70° pick an object off the ground
- 85° to climb up stairs
- 95° to stand from a sitting position
- 105° to tie shoelaces
- 115° (or greater) to squat or sit cross-legged
- 125°+ covers most activities. However, squatting or sitting on your heel may always prove challenging.