Stiffness four months after meniscus surgery should first be identified as the cause of the problem, and then physical therapy or surgery should be carried out. The causes of stiffness four months after meniscus surgery include muscle atrophy and soft tissue adhesion. It is recommended to identify the cause of the disease before treatment and target treatment. 1. Muscle atrophy: If the patient is braked for a long time after the operation, it is easy to cause muscle atrophy, and then there is a lack of muscle strength, resulting in stiffness of the knee joint, the patient can gradually carry out sports training to enhance muscle strength, which can improve the stiffness. 2. Soft tissue adhesion: after meniscus surgery may have soft tissue adhesion, can be manipulated to loosen, red light therapy, local hot packs, promote local blood circulation, relieve adhesion, can also be ultrasound therapy, to loosen the adhesion, but also can be appropriate stretching training, to loosen the adhesion of tissue, if it is difficult to alleviate, can be used to loosen the surgery. Four months after the meniscus surgery is still stiff should be timely medical treatment, by the doctor to clarify the cause of the disease, choose the appropriate treatment, the patient should pay attention to actively cooperate with the doctor to carry out rehabilitation training.