Inability to bend 4 months after tibial plateau fracture is mainly caused by poor postoperative functional exercise. It is necessary to strengthen the functional exercise, and ligament release under local anesthesia is needed in serious cases. Tibial plateau fracture 4 months after surgery can not be bent surface knee flexion dysfunction, mainly because the tibial plateau fracture after surgery needs to be fixed in the straight position, in order to promote fracture healing, when the long-term straight position fixation leads to postoperative joint function exercise is poor, it is easy to cause postoperative knee flexion dysfunction. For those who have knee flexion disorder 4 months after surgery, the fracture has basically formed a stable bone scab at this time, so they can carry out knee joint functional exercise, and gradually increase the degree of tolerance according to the exercise, in order to achieve the recovery of knee flexion function. For those who still have knee flexion obstacles after functional exercise, they can be treated with ligament laxation under local anesthesia or femoral nerve block anesthesia, and continue the functional exercise after the operation. Those who are unable to bend the knee 4 months after tibial plateau fracture need to consult the doctor as soon as possible and receive appropriate treatment, so as to avoid the aggravation of knee dysfunction leading to joint deformity.