Costo-vertebral angle in a toddler, costo-vertebral joint. The costo-vertebral angle is the angle formed by the rib with respect to the vertebra at the level of the joint between these two bones. Small anatomical reminder, the ribs articulate with the corresponding vertebrae at the costo-vertebral joints. These joints consist of two joints for each rib. The first joint is the costo-corporeal joint which is located between the costal head and the vertebral body of two vertebrae. It is invisible in this view. The second joint is located between the costal tuberosity and the transverse process of the lower vertebra. It is the costo-transverse joint, visible on this posterior view. In a toddler's rib cage, the angle between the ribs and the vertebrae forms a right angle. Associated with a flat diaphragm, the rib cage plays little part in the ventilation effort. It is also noted that the proportion of cartilaginous structure (in blue) in the vertebrae and ribs in children is greater than it will be in adults.