I’m at the very beginning of week 6. My ROM with bent leg is at 97 today. I feel like my progress is slow and I’m always stiff and still have pain. Will I be able to move past this? Do people ever get “stuck” and stop improving with range of motion?
A flexion of 97 degrees at only 6 weeks post-op is pretty good. I'd say you're making good progress.
By the way, ROM (Range of Motion) consists of both flexion (bending) and extension (straightening).
Complete recovery from a knee replacement takes a full year, although you won't always feel like you do now. By about 3 months, you'll be able to do almost everything. But, you have had major surgery, not the sort you can recover from in just a few weeks. If you think of it as a race, it's a marathon, not a sprint, so you have to pace yourself.
It's normal to still have stiffness and pain at 6 weeks. They'll decrease gradually, but the stiffness sometimes lingers for several months.
Of course you're going to move beyond this, but you will have some periods when you seem to be standing still and even some when you seem to lose ground. Recovery isn't a straight linear progress. It's more like this:
There's no need to rush to get ROM, because it can continue to improve for a year, or even much longer, after a knee replacement. There isn't any deadline you have to meet:
Myth busting: the "window of opportunity" in TKR