The three bones that come together to form the elbow can break (fracture) in different ways. A distal humerus fracture is one type of elbow fracture. The distal humerus is the end of the upper arm bone (the humerus) that forms the upper part of the elbow. These types of elbow fractures are fairly uncommon. They account for about 2% of fractures in adults. The elbow is a complicated joint and elbow fractures can involve both of the forearm bones, as well as the humerus.