If there is significant pain when the knee is flexed, the cause needs to be identified. If the knee joint is painful when bending due to osteoarthritis of the knee joint, most of them can be treated with non-steroidal drugs first. Most of the non-steroidal anti-inflammatory drugs in the clinic choose ibuprofen, aminophenol dihydrocodeine tablets, diclofenac sodium, these drugs have very good anti-inflammatory, analgesic effect, for knee pain, aseptic inflammation, have very good therapeutic effect. If the pain is triggered during flexion and extension due to meniscal injury or wear, you can also take non-steroidal drugs with decongestant drugs, such as Diosmin, Mizarin, and sodium heptaerythrone, most of these drugs have very good decongestant and analgesic effects on local limb edema and swelling caused by trauma. You can also take cartilage-protective drugs such as glucosamine sulfate.