In 1988, a group led by R.B. Wagner divided pulmonary lacerations into four types based on the manner in which the person was injured and indications found on a CT scan.^[1]

• In type 1 lacerations, which occur in the mid lung area, the air-filled lung bursts as a result of sudden compression of the chest.^[1] Also called compression-rupture lacerations, type 1 are the most common type and usually occur in a central location of the lung. They tend to be large, ranging in size from 2–8 cm.^[2]
• The shearing stress in type 2 results when the lower chest is suddenly compressed and the lower lung is suddenly moved across the vertebral bodies.^[1][2] Type 2, also called compression-shear, tends to occur near the spine and have an elongated shape.^[2] Type 2 lacerations usually occur in younger people with more flexible chests.^[3]
• Type 3, which are caused by punctures from fractured ribs, occur in the area near the chest wall underlying the broken rib.^[1] Also called rib penetration lacerations, type 3 lacerations tend to be small and accompanied by pneumothorax.^[1] Commonly, more than one type 3 laceration will occur.^[2] Type 4, also called adhesion tears, occur in cases where a pleuropulmonary adhesion had formed prior to the injury, in which the chest wall is suddenly fractured or pushed inwards.^[2] They occur in the subpleural area and result from shearing forces at sites of transpleural adhesion.^[3]