The term “bone marrow edema” often appears in hospital tests or diagnostic results, and some clinicians do not know what it means or the severity of the disease, and, of course, the patient or family members do not know what it means. How can bone marrow edema be detected by examination? Bone marrow edema is a sign with bone matrix edema, fibrous tissue proliferation and inflammatory cell infiltration as the main pathological manifestations. With the development of science and technology and the wide application of MRI, the sign of bone marrow edema has been gradually recognized, but it has not attracted widespread attention until recent years when some scholars have conducted relevant research reports. The causative factors of bone marrow edema are still uncertain, including: trauma, hormones, and mechanical stress changes. Altered biomechanics is one of the causes of myeloedema, and mechanical stress may play an important role in the development of myeloedema. Mechanical stress alterations lead to fracture of the trabeculae in the weight-bearing area and bone marrow edema.MRI is currently the best means of diagnosing and evaluating bone marrow edema. The degree of pain is consistent with the severity of myeloedema, and as the severity of myeloedema decreases on MRI, the patient’s pain decreases accordingly. In this case, it should be a patellofemoral problem, which is caused by the increase in stress on the patella due to the amount of repetitive bending of the knee, which is a relatively rare case and is easily misdiagnosed. Bone marrow edema syndrome usually occurs in the hip joint. The term “bone marrow edema” emerged with the use of Magnetic Resonance Imaging (MRI), which means that the presence of bone marrow edema at an early stage can only be detected by an MRI examination, which is sensitive to water and the bone marrow edema shown is more characteristic, so that the diagnosis can be made directly. That is, the area of bone marrow edema is white on the T2WI pressure lipid image of MRI and black on T1WI. Other imaging tests are not able to detect or diagnose bone marrow edema (including X-rays, CT, PET-CT, ultrasound, etc.).