Avulsion injury

In medicine, an avulsion is an injury in which a body structure is torn off by either trauma or surgery (from the Latin avellere, meaning "to tear off"). The term most commonly refers to a surface trauma where all layers of the skin have been torn away, exposing the underlying structures (i.e., subcutaneous tissue, muscle, tendons, or bone). This is similar to an abrasion but more severe, as body parts such as an eyelid or an ear can be partially or fully detached from the body. The most common avulsion injury, skin avulsion often occurs during motor vehicle collisions. The severity of avulsion ranges from skin flaps (minor) to degloving (moderate) and amputation of a finger or limb (severe). Suprafascial avulsions are those in which the depth of the removed skin reaches the subcutaneous tissue layer, while subfascial avulsions extend deeper than the subcutaneous layer. Small suprafascial avulsions can be repaired by suturing, but most avulsions require skin grafts or reconstructive surgery. In rock climbing, a "flapper" is an injury in which parts of the skin are torn off, resulting in a loose flap of skin on the fingers. This is usually the result of friction forces between the climber's fingers and the holds, arising when the climber slips off a hold. To fix this injury and to be able to continue climbing, many climbers will apply sports tape to the flapped finger to cover up the sensitive area of broken skin. Some climbers may even use super-glue to adhere the loose skin back to the finger. The ear is particularly vulnerable to avulsion injuries because of its position on the side of the head. The most common cause of ear avulsions is human bites, followed by falls, motor vehicle collisions, and dog bites. A partially avulsed ear can be reattached through suturing or microvascular surgery, depending on the severity of the injury. Microvascular surgery can also be used to reattach a completely avulsed ear, but its success rate is lower because of the need for venous drainage.