What does a proximal humerus fracture mean? A proximal humerus fracture is a fracture that occurs at the proximal end of the humerus, as the name implies. The bone that makes up our upper arm is the humerus. The distal end of the humerus is part of the elbow joint and the proximal end is part of the shoulder joint. Because the proximal humerus is adjacent to the shoulder joint, fractures that occur here often involve the internal structures of the shoulder joint and are intra-articular fractures, which are different from the long tubular bones of the extremities.