Any anomaly of the costochondral junction. The costochondral junctions are located between the distal part of the ribs and the costal cartilages, which are bars of hyaline cartilage that connect the ribs to the sternum.
Comment:
The first seven pairs of ribs are connected with the sternum; the next three ribs are each articulated with the lower border of the cartilage of the preceding rib; the last two ribs have pointed extremities, which do not connect with the sternum.