The main causes of osteomalacia of knee joint are rheumatoid arthritis, osteoarthritis, septic arthritis, etc. According to the cause of the disease, anti-rheumatic drugs, appropriate exercise, incision and drainage, etc. can be taken to treat the disease. 1. Rheumatoid arthritis: rheumatoid arthritis can cause inflammation of the knee joint, and some of them can be accompanied by osteomalacia of the knee joint, and the progress of the disease can be slowed down by taking antirheumatic drugs such as methotrexate and salazosulfapyridine. 2. Osteoarthritis: Osteoarthritis of the knee joint can appear cartilage degeneration, joint edge osteophytes, etc., which can lead to knee pain during activities and can be relieved after resting, so unnecessary weight-bearing exercise of the knee joint should be avoided as much as possible, such as climbing stairs, squatting, etc. If pain is severe, oral medication can be taken. When the pain is severe, non-steroidal anti-inflammatory drugs such as ibuprofen can be taken orally, and chondroitin sulfate and other nutritive cartilage drugs can also be taken. 3. Purulent arthritis: Purulent infection in the knee joint cavity can lead to bone destruction, causing osteomalacia, which requires intra-articular injection of antibiotics, and if the treatment is ineffective, continuous irrigation or incision and drainage of the joint cavity is required. All of the above medications should be used under the guidance of a doctor, avoid self-medication. In case of osteomalacia of the knee joint, it is recommended to consult a doctor in a timely manner to clarify the cause of the disease and to carry out targeted treatment or therapy with the help of a doctor.