The shoulder is made up of the clavicle (collar bone), humerus (upper arm) and scapula (shoulder blade). The shoulder is a ball and socket joint where the ball of the upper arm bone articulates with the socket of the shoulder blade called the glenoid cavity. The shoulder blade is a flat triangular bone present on either side of the upper back. It articulates with the other two bones at the glenohumeral joint and acromioclavicular joint to provide stability and mobility to the arm. Scapula fracture refers to a fracture of the shoulder blade. Scapula fractures can result from severe trauma such as a motor vehicle accident, a fall from a height, contact sports, a fall on an outstretched arm and direct blow on the shoulder during a fight.