Total knee arthroplasty surgery for the elderly is only one aspect of disease treatment, postoperative care, functional exercise and long-term daily care are also part of the treatment and should be taken seriously. The precautions are as follows: 1. Observe the affected limb with a cushion underneath the affected limb, elevate it 20° to 30°, and closely observe the peripheral blood circulation, sensation, skin temperature, and movement of the affected limb. Prevent venous embolism of the lower extremity and osteo-fascial compartment syndrome from developing; 2. Prevention of venous thrombosis Due to the long post-operative bed rest time of the elderly, the incidence of venous thrombosis in knee arthroplasty is about 40% to 50% due to sluggish venous blood flow and hypercoagulation of blood. Therefore, patients should be encouraged to do active or passive flexion and extension exercises of the ankle and knee joints, and perform muscle contraction early to improve the circulation of the lower limbs by using the “muscle pump” to avoid its occurrence. The use of anticoagulant drugs after surgery can prevent and greatly reduce the incidence of embolism; 3, drainage tube care properly placed drainage tube, do not twist, folding, pressure, to ensure smooth drainage. Observe the nature, color and amount of drainage fluid, shift handover and keep records. If the drainage is less than 50 ml, the drainage tube can be removed; 4. Prevention of infection Prevention of knee infection is an extremely important part of post-operative care for artificial knee replacement, which directly affects the quality of surgery. Nursing staff must closely observe changes in body temperature, which can occur within 3 days after surgery as low to moderate fever, mostly absorption fever. If there is a significant increase in body temperature after surgery, accompanied by wound pain and joint swelling, it indicates the occurrence of infection, which should be reported to the physician promptly, and effective antibiotics should be selected and handled accordingly. In addition, increase the nutritional intake to improve the immunity of the body; 5. Prevent pulmonary and urinary tract infections 1 d after surgery, you can sit up properly in bed to prevent the occurrence of pneumonia; encourage patients to cough more and turn and pat their backs, drink more water to prevent urinary tract infections; 6. Post-discharge precautions explain to patients and families that the functional rehabilitation of the knee joint takes a long time, and you must continue to enhance muscle strength and knee flexion and extension activities after discharge. Exercise. After the balance of gait training, balance function is good, carry out resistance to moderate resistance and other tension training, the situation allows the abandonment of crutches or off the walker, walking speed, endurance training, up and down stairs training. At the beginning, slope walking, correct all kinds of abnormal gait, until walking freely. Strive to restore to 85%-90% of normal muscle strength. Continue to strengthen the functional exercise of the knee joint, avoid running, jumping, weight-bearing and other activities to prevent the knee joint prosthesis from bearing too much force; 7. The ultimate goal is to reduce the patient’s pain and improve his or her quality of life through artificial knee arthroplasty. Whether the surgery can achieve the desired purpose is influenced by many factors such as swelling of the affected limb, pain, rehabilitation exercises, and postoperative complications. Therefore, proper postoperative care, close observation of the condition, active prevention of complications, development of an overall rehabilitation plan, promotion of early functional exercise, and also strengthening of psychological care can reduce the patient’s pain, prevent the occurrence of complications, promote the recovery of knee function, reduce hospitalization time and economic costs, improve the patient’s quality of life, and restore normal or near-normal life as soon as possible.