Knee pain can be caused by the following reasons: First, quadriceps tendonitis, quadriceps tendonitis is often due to chronic strain or due to long-term sports, resulting in chronic injury to the quadriceps muscle, resulting in pain above the knee joint, then we should early check the knee MRI, the quadriceps tendon on the MRI is often an abnormal injury signal, then we need to early line physical therapy and local closed treatment, so as to effectively relieve pain and reduce inflammation. This can effectively relieve pain and reduce inflammation. Secondly, bursitis of suprapatellar bursa, when the bursa of suprapatellar bursa has chronic inflammation, the pain at the suprapatellar bursa above the knee joint can also appear, which can be accompanied by joint cavity effusion and joint activity limitation, and then we should have an early checkup and examination of the MRI of the knee joint to make an early diagnosis, and need to carry out the arthritic cavity puncture and surgical treatment if necessary.