I am 18 months post op, and my experience was similar to yours.
I went back to physical therapy 7 months post op because I could not run. My PT said I had muscle imbalances: strong quads and hamstrings from all the walking I had done, and weak muscles on the sides of my thigh. We did a lot of strengthening exercises and some stretching. It took a couple of months, but I can now run. Just did my first actual race yesterday.
Hoppie