The knee joint interlocking is mostly due to meniscal injury, the ruptured and displaced meniscus is stuck in the joint space, so that the knee joint cannot move normally. The technique to release the interlock is as follows: the patient lies supine and flexes the knee and hip 90 degrees, an assistant holds the lower end of the patient’s femur, the physician holds the ankle joint, the two pull each other, the physician rotates the calf inside and outside several times, then makes the calf flex as much as possible, then straightens the lower limb, the interlock can be released. If a single person operation, the patient supine bending knee and hip 90 degrees, the doctor with the axillary hold the patient ankle, one hand on the lower end of the outer calf, the other on the inner knee, the doctor backward pull the calf, ask the patient to grasp the edge of the bed with both hands to form a confrontation traction knee joint, the rest of the techniques as above.