Age 26 left knee acl reconstruction (BTB method) Even 11 months after my knee surgery being with high class professional physiotherapy I am having 2 cm height Hard and bumpy swelling on lateral side of knee which is not allowing knee flexation not more than 130 degree 0-1 degree hyper extension and feeling high discomfort while walking and painful while sitting on low height chairs/stools What is the reason? Is this serious problem? How to solve this (3 physiotherapists operated on me till now)