After joint surgery, doctors usually apply cold and heat therapy to promote recovery. The so-called cold therapy (cold therapy) is the use of lower-than-body-temperature media interventions to cool down to achieve the purpose of treating the disease. There are various methods, the most common of which are ice, ice water immersion and cold spray. In the recovery period of joint disease injury, the most commonly used cold therapy method is ice. First, the impact of cold therapy for joint surgery after joint injury, reasonable cold therapy can have some advantages: 1, reduce pain Cold therapy can reduce the speed of sensory and motor nerve conduction, slow the release of histamine, reduce tissue sensitivity to pain, reduce the use of pain medication; 2, reduce bleeding and exudation Cold therapy can be local tissue vasoconstriction, reduce post-injury or post-surgical microcirculation and surrounding Tissue exudation and swelling; reduce the role of vascular endothelial cells and thrombus formation; reduce the release of oxygen free radicals and so on. Second, the timing of cold therapy after joint surgery 1, the acute postoperative period, especially within the first 24 hours after surgery, microcirculatory disorders and their secondary tissue damage response is not obvious. It can reduce bleeding, pain and swelling. At this time, it is recommended that the frequency of ice compresses can be increased intermittently. 2, postoperative rehabilitation period in the rehabilitation training such as joint mobility exercises, as well as after a long period of standing, walking, holding, weight bearing, or usually feel the joint or limb swelling, pain, fever is obvious, you can local cold therapy in the affected area for 15-20 minutes, when using should pay attention to protect the wound clean and dry. Third, the contraindications and precautions for cold therapy: 1, combined with Raynaud’s disease, paroxysmal cold hematocrit urine, condensation globulinemia and other circulatory disease disorders; 2, low or elderly patients who can not tolerate cold therapy; In short, for patients with hypertension, cold allergy, fear of cold, circulatory system abnormalities, people with wound sites or psychological disorders, etc., in cold therapy should be particularly careful to avoid In contrast to cold therapy, heat therapy, i.e. In contrast to cold therapy, heat therapy is a method that uses the temperature of the affected area to increase to achieve the purpose of treatment. There are many types of heat therapy, including heat packs, wax therapy, particle therapy, infrared radiation, hydrotherapy, ultrasonic therapy, etc. Heat therapy has a relaxing and calming effect, and centuries ago it was known to apply heat to injured tissues to reduce muscle spasm. In physical therapy, heat therapy is not only used to promote relaxation, but also to increase blood flow, promote tissue healing, and to prepare stiff joints and tense muscles for exercise. There is a wide variety of heat therapy modalities that can be used for a variety of conditions, notably superficial heat therapy and divine deep heat therapy. The so-called superficial heat therapy refers to the maximum heat (about 40~45°C) in the range of acceptable clinically safe temperatures, and its thermal impact and effect can only increase the temperature of surface tissues, for example, heat packs, wax therapy, hydrotherapy, etc. are superficial heat therapy; while deep heat therapy refers to the conversion of any form of energy into thermal energy, which can pass through the skin, through the deep tissues, and cause them to be absorbed, resulting in an increase in deep tissue temperature and molecular activity increases, such as electronic waves, ultrasound, etc. Heat therapy in bone and joint diseases and postoperative rehabilitation: 1. Heat therapy is often used for stiffness of joints and muscles in bone and joint diseases and before postoperative rehabilitation exercises, although it should be noted that heat therapy should not be used in the early postoperative period after joint surgery, as it can aggravate bleeding in the joint cavity. 2, the specific use of conservative treatment patients can use heat therapy when the joint pain, flexion and extension unfavorable, depending on the specific time of heat therapy, about 20-30 minutes at a time, should not be too long; joint surgery after the acute edema period (depending on the type of surgery, generally 3-7 days, joint replacement patients may be slightly longer) before the rehabilitation exercise, you can also perform 15-20 minutes of heat therapy, and then This will allow for better rehabilitation. Contraindications to heat therapy: 1. patients with a lack of integrity of temperature perception are not suitable for heat therapy because of the possibility of burns; 2. the acute bleeding phase of the injury contraindicates the use of heat therapy; 3. the use of heat therapy is contraindicated in patients with malignant tumors at the site of heat therapy.