Pain in the knee may not necessarily be bone cancer, but may have the following causes: 1. Local injury: it is often an injury pain caused by trauma or overwork, which is related to medical history, such as strenuous activities, sports or other external forces on the knee joint, and combined with local imaging examination, it can be further judged and further treated under surgical guidance; 2. Rheumatic diseases: rheumatoid arthritis may also cause knee pain, usually bilateral and symmetrical, along with inflammatory changes of redness, swelling, heat and pain. Patients can further consult the Department of Rheumatology and Immunology to improve the relevant immune index examination, so as to guide the systemic treatment, improve the symptoms and quality of life; 3, malignant tumor: malignant tumor can also cause local pain, and local nuclear magnetic or bone scan examination can be performed to determine whether it is due to malignant tumor bone metastasis, so as to guide the subsequent treatment and assess the prognosis.