The following are common causes of knee pain symptoms in the elderly: 1. Degenerative osteoarthritis, the most common cause of knee pain in elderly patients, can be detected by MRI, which reveals extensive cartilage exfoliation of the joint surface, exposed subchondral bone, and severe sclerosis of the joint surface, and most patients will have joint pain, limited movement, and have joint stiffness in the morning. 2. Meniscal injury of the knee, the meniscus The meniscus tears during long-term overweight or overuse, and the patient will have knee pain, restricted movement, and even severe joint interlocking symptoms. Elderly patients with knee pain should be treated promptly to improve clinical symptoms, and should also strengthen the muscle strength and intensity training of the legs in general to further protect the knee joint.