Chest injuries are quite properly divided, for clinical purposes, into two large groups: nonpenetrating wounds and penetrating wounds. The distinction is the obvious one that in the latter there is a break, greater or less in extent, in the normally hermetically sealed thoracic cavity, while in the former such a disruption does not occur. The categories are not entirely mutually exclusive, as an injury producing multiple segmental rib fractures, while not a penetrating wound, may nevertheless produce all the disturbances of physiology present in the most severe types of penetrating wounds. With such obvious exceptions, however, the classification of wounds as penetrating and nonpenetrating serves admirably for diagnostic and therapeutic purposes.
Severe contusions of the chest wall producing such bizarre injuries as fractures of the sternum, chondrosternal separation of the ribs, traumatic rupture of a lung, traumatic asphyxia and contusions of the heart do occur in civilian life
McGRATH EJ. WOUNDS OF THE CHEST. JAMA. 1944;124(8):488-491. doi:10.1001/jama.1944.02850080016005