Knee clicking can be caused by physiological factors, patellofemoral osteoarthritis, meniscus injury, etc., and can be treated with general therapy, medication and surgery. 1. Physiological factors: knee tendon and bone friction in the flexion and extension movement can appear clicking performance, not accompanied by pain in the knee joint, this situation generally do not need to be dealt with, if necessary, can be clarified by a doctor. 2. Patellofemoral arthritis: patellofemoral arthritis can lead to patellofemoral articular cartilage wear and tear, friction in the activities of the joint surface is not smooth can appear clicking and other strange sounds. It is necessary to protect the knee joint, reduce hiking, up and down stairs, squatting and other actions. Under the guidance of specialists, puncture of the knee joint can be carried out, and drugs such as sodium vitrate can be injected into the joint cavity to help lubricate and nourish the articular cartilage and reduce local friction, and when the condition is serious, arthroscopic surgery or arthroplasty is required. 3. Meniscus injury: trauma or sports injuries can cause meniscus injury, meniscus tear is easy to be stuck between the femur and tibia, when the knee joint activities can appear clicking sound. After the meniscus injury need to perform knee braking, reduce local activities, can be in the regular hospital for local physical therapy and quadriceps exercise, meniscus injury is serious need to perform arthroscopic resection or repair treatment. When the knee joint clicks should be timely medical treatment, after the condition is clear, under the guidance of the doctor to actively carry out appropriate treatment, which will help to relieve the local discomfort symptoms as soon as possible.