The causes of bone marrow edema, or a bone bruise, in the shoulder include traumatic injury and arthritis, according to About.com. Osteonecrosis, a lack of blood flow to the bone, may also cause bone marrow edema.
Traumatic injury is a common cause of bone bruising, and it is often due to overuse or an acute injury, explains About.com. Doctors most commonly diagnose an injury in the bone by using magnetic resonance imaging. Most doctors recommend rest when this occurs, as the bone and joints must heal. It can take weeks or even months for an injury to the bone to fully heal, however.
Arthritis is another cause of bone marrow edema, and in this case, there is damage to the cartilage at the surface of the joint, states About.com. This cartilage helps to cushion and shield the bone, and when it becomes weak or experiences damage, it exposes the bone to stress. Those who have arthritis often experience symptoms of bone marrow edema in the same areas where they have arthritis.
Osteonecrosis may also cause bone marrow edema, and this occurs when there is an interruption to the blood supply to the bone, claims About.com. The lack of blood to the bone may weaken it, and if it becomes week, it may develop microfractures. These small fractures can cause bone bruising in the area with osteonecrosis.