I Had A Total Right Knee Replacement Aug.28,2013. I Did

I had a total right knee replacement Aug.28,2013. I did my therapy twice but still couldn't straighten my knee. The bending was good but I couldn't straighten the knee. I realize scare tissue has set in and I would like to know if they would go in a remove the scare tissue and stretch the muscles in the rear of my leg it would greatly help along with therapy to enable me to walk correctly?