Hi @dsoda - Welcome to Connect! There are lots of people here with great experience to share. I'm wondering how long ago was your partial knee replacement? If it was just a short time, I think you can look forward to great improvement. I'm also wondering what kind of pain meds you are taking? For me, it was important to take my pain meds before PT - otherwise it hurt too much to really accomplish anything. I've heard some people who tried to get off the pain meds too soon and they regretted it later when PT didn't work as well.

I just had a total knee replacement in January and the difference between my flex & extension leaving the hospital vs. now after one month is major. I'm at 128 degrees flexion, but I'll say this - there are a lot of people on this forum who never even get to 120 but end up being perfectly comfortable with getting around and doing their regular activities. Also, you asked about use of the walker, I was off the walker in my 2nd week when I started using a cane. At this point, I'm walking around the house w/o the cane, but I use it when I go outside or in the evenings when my knee is more tired.

Here is an article about manipulation under anesthesia (MUA).
https://www.mayoclinic.org/medical-professionals/orthopedic-surgery/news/animal-models-aid-study-of-arthrofibrosis-after-tka/mac-20429402
I'm hoping you feel better every day. Best of luck.