If a girl is thin and has less fat and muscle in the knee area, the knee may bulge out, which is a normal physiological phenomenon and requires no special treatment. The actual fact is that the girl’s knee may be bulging out. This is usually relieved by taking calcium gluconate tablets, vitamin D, and sun exposure, and increasing the intake of milk and meat; 2, osteosarcoma: a common malignant tumor disease of the bones, usually caused by infection with a virus, which can cause local swelling, pressure pain and other symptoms, and sometimes weight loss, fever and other phenomena, the tumor will also appear when the larger knee bulge out. 3, tibial nodal epiphysitis: usually due to acute or chronic injury, and patients have a greater relationship with long-term exertion, will lead to bone pain, activity obstruction and other symptoms, due to local inflammation stimulate the epiphysis at the hyperplasia, sometimes protrude the bone surface, can make the girl’s knee protrude, usually need to follow medical advice to take Diclofenac sodium extended-release tablets, acetaminophen and other medications, pain can be taken when the obvious prednisolone local closed injection treatment; 4, osteophytes: often due to joint cartilage strain or long-term poor posture caused by frequent weight bearing, sports, etc. will also appear osteophytes, the main symptom of the lesion is that it will make the knee protrude, but also affect the normal movement of girls, this can be done by following medical advice The main symptom of this lesion is that it makes the knee bulge out, and also affects the normal movement of the girl, so the pain can be relieved by using ibuprofen extended-release tablets and celecoxib capsules as prescribed by the doctor, and at the same time the weight bearing and substantial activities of the joint should be reduced; 5. It is usually treated by osteochondroma resection.