Post-op recovery

I had my first session of Physical Therapy (PT) last Wednesday. I'll be going 2 times a week for the next few weeks. My knee feels OK but gets tired easily. The therapist explained that any damage to the knee causes the thigh muscles (quadriceps) to "shut down" and PT is intended to awaken the muscle and build strength.

I have been doing PT at home at least once per day, sometimes twice. I'm supposed to do it 3 times, but have not been able to make the time. I'm able to bend my knee 120 degrees which is pretty good compared to my good knee (135 degrees). I do feel that my knee buckles from time to time when I'm walking but I'm told that will go away when the quad is stronger.