I had both knees replaced Dec. 2019. At my one year appointment I again told Doctor of that tightness in Left knee when I bend it even a little bit. It does not bend as well as right knee, turning with sleep in painful. Always feels tight, takes effort to get in and out of cars. Early on he said it would resolve, now he says it’s scar tissue and to fix it I would need manipulation, done under anesthesia to break up scar tissue. Said it’s 80 percent effective. I’ll do it after I am vaccinated.