Proximal humerus fracture Proximal humerus fracture A proximal humerus fracture is a break of the upper part of the bone of the arm (humerus). Symptoms include pain, swelling, and a decreased ability to move the shoulder. Complications may include axillary nerve or axillary artery injury. The cause is generally a fall onto the arm or direct trauma to the arm. Risk factors include osteoporosis and diabetes. Diagnosis is generally based on X-rays or CT scan. It is a type of humerus fracture. A number of classification systems exist. Treatment is generally with an arm sling for a brief period of time followed by
Bone marrow in the central skeleton, such as the pelvis, sternum, cranium, ribs, vertebrae and scapulae, and variably found in the proximal epiphyseal ends of long bones such as the femur and humerus. In circumstances of chronic hypoxia, the body can convert yellow marrow back to red marrow to increase blood cell production. At the cellular level, the main functional component of bone marrow includes the progenitor cells which are destined to mature into blood and lymphoid cells. Marrow contains hematopoietic stem cells which give rise to the three classes of blood cells that are found in circulation: white blood cells (leukocytes),