Osteoporosis (OP) and Knee osteoarthritis (KOA) are diseases that harm the bone health of middle-aged and elderly people. There are a large number of patients suffering from these two diseases simultaneously. Total knee arthroplasty (TKA) in such patients is difficult to treat, and complications such as postoperative pain, prosthesis loosening, periprosthetic fracture, and increased revision risk seriously affect the quality of life of patients. Therefore, both doctors and patients need to be aware of the serious harm of these two diseases. To evaluate the severity of osteoporosis in patients with knee osteoarthritis, and to reduce the further loss of bone mass and maintain good bone condition through early medication.