Lesions can be transverse, occurring between the rings of the trachea, longitudinal or spiral. They may occur along the membranous part of the trachea, the main bronchi, or both.[2] In 8% of ruptures, lesions are complex, occurring in more than one location, with more than one type of lesion, or on both of the main bronchi and the trachea.[2] Transverse tears are more common than longitudinal or complex ones.[9] The laceration may completely transect the airway or it may go only partway around. Partial tears that do not go all the way around the circumference of the airway do not allow a lacerated airway to become completely detached; tears that encircle the whole airway can allow separation to occur.[10] Lacerations may also be classified as complete or incomplete.[4] In an incomplete lesion, a layer of tissue surrounding the bronchus remains intact and can keep the air in the airway, preventing it from leaking into the areas surrounding the airways.[11] Incomplete lacerations may require closer scrutiny to detect[12] and may not be diagnosed right away.[11]