Knee doesn’t bend well

Good that you're staying proactive about this at 44 - that mindset matters a lot. Since you're dealing with arthritis and some uncertainty about what's driving the restriction, I'd really encourage you to loop in your doctor or a physical therapist first so they can pinpoint exactly what's limiting that bend. Once you have some clarity there, gentle work on hip alignment and how you load the knee can make a real difference, and my Knee Pain Relief program is designed to support that kind of movement restoration. Hang in there - there's usually a lot you can do before anything surgical needs to be on the table.