Leg cramps after knee arthroplasty need to be treated according to the cause. There are many reasons for leg cramps, such as lower extremity vascular disease, calcium deficiency, cold stimulation, etc. 1. Lower extremity vascular disease: If the blood vessels of the lower extremity are subjected to tourniquet pressure during knee arthroplasty or postoperative rehabilitation training is not appropriate, it may lead to venous thrombosis, and if it affects the blood supply to the legs, leg cramps may occur. Follow the doctor’s instructions to give anticoagulation and thrombolytic therapy, such as the use of urokinase, low molecular heparin sodium and other drugs. 2. Calcium deficiency: Calcium deficiency will make the concentration of calcium ions in the blood too low, and the muscles will contract excitedly, resulting in leg cramps. It is recommended to take calcium carbonate tablets to replenish the calcium content in time. 3. Cold stimulation: If the legs are stimulated by the cold environment, it may affect the blood circulation in the legs, resulting in involuntary muscle contraction and leg cramps. It is recommended to pay attention to keep warm in daily life, avoid contact with cold environment as much as possible, and improve blood circulation through physical therapy or hot compresses to relieve leg cramps. Epilepsy, high fever and other diseases may also cause leg cramps. If you experience leg cramps after knee replacement, it is recommended that you consult a doctor and take appropriate treatment according to the cause of the cramps.