How many degrees can be loosened by knee joint release surgery depends on the condition, surgical method and other factors. Under normal circumstances, through active treatment, the knee joint can be flexed to 100°~135°. The normal degree of knee flexion and extension is 0°~140°. After long-term joint mobility limitation, not only adhesions will be generated in the joint cavity, but also the corresponding tissues, such as muscles, ligaments and joint capsules around the joint, will be contracted, i.e., the length will be shortened and the ductility will be reduced, which will aggravate the joint mobility limitation. It is difficult to reach the angle of intraoperative loosening and pushing for a long period of time after surgery, and it is necessary to stretch the corresponding tissues through long-term functional exercises to make them lengthen gradually in order to obtain good joint movement. In general, recovery to flexion of 100° or more will not affect daily life.