Bone marrow edema of the knee may recur when the primary disease is not cured, or when the knee is re-injured, but it is not absolute. Knee bone marrow edema, a condition in which there is an excessive accumulation of fluid in the extracellular space of the knee joint, can be caused by a variety of diseases and injuries, such as direct trauma, infectious arthritis, and bone tumors. Bone marrow edema of the knee joint can be cured and will not recur if the bone marrow fluid is discharged or absorbed through systematic treatment. However, if the primary disease is not cured and the damaging factors to the knee joint still exist, it may lead to recurrence of knee bone marrow edema. In addition, if the factors that damaged the knee joint reappear after the disease has healed, the edema may also reoccur. Patients with knee edema need to undergo appropriate examinations in the hospital to clarify the cause of the disease and to treat the primary disease, and also pay attention to the protection of the knee joint after recovery to avoid recurrence of the disease.