I have a knot on the back outside of my knee that is tender and sore. I have had heaviness to the knee, locking, and pain. The pain is pretty constant, varying in intensity. It bothers me with simple tasks, like getting dressed or getting out of the car and straightening it. It wake me and keeps me up from time to time.I have seen a doctor and had an MRI, but the MRI was negative. He sent me to physical therapy for 2 months, which helped the treatment, but the pain returned almost immediately upon exercise.