Limited bone marrow edema of the right patella, distal femur and proximal tibia may be caused by muscle injury, ligament injury and trauma of the knee joint. 1. Knee joint muscle injury: the knee joint is surrounded by rich muscles, tendons and other soft tissues, and poor posture or prolonged fatigue exercise will lead to muscle injury at the knee joint, resulting in inflammatory reaction and bone marrow edema of the patella, distal femur and proximal tibia. 2. Knee ligament injury: long-term climbing, jogging and other sports, or sudden turning, bending legs, etc. will cause ligament injury, so that the ligament localized congestion, edema and other reactions, which will lead to the situation. 3. Trauma: under the collision of external force, it will cause the knee joint to have hedonic extrusion, which will make the patella damage and trigger the situation. When there is limited bone marrow edema of the right patella, distal femur and proximal tibia, it is necessary to go to the regular hospital in time to get a clear diagnosis.