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").
Skin avulsions
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).
fascia 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.
[Jeng, S.F., & Wei, F.C. (1997, May). Classification and reconstructive options in foot plantar skin avulsion injuries. Plastic And Reconstructive Surgery, 99(6), 1695-1703.] Small suprafascial avulsions can be repaired by suturing, but most avulsions require skin grafts or reconstructive surgery.
Rock climbing
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.
[ Flapper - n. a superficial injury resulting in a loose flap of skin. , Climbing Dictionary, Rockclimbing.com] This is usually the result of friction forces between the climber's fingers and the
Climbing hold, 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.
Ear avulsions
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 are bite injuries, primarily human-inflicted, followed by motor vehicle accidents, burns, and complications resulting from
Otoplasty.
A partially avulsed ear can be reattached through
suturing or microvascular surgery, depending on the severity of the injury.
[Nahai, F., Hayhurst, J. W., & Salibian, A. H. (1978, July). Microvascular surgery in avulsive trauma to the external ear. Clinics in Plastic Surgery, 5(3), 423-426.][Fleming, J. P., & Cotlar, S. W. (1979, July). Successful reattachment of an almost totally avulsed ear: Use of the fluorescein test. Plastic and Reconstructive Surgery, 64, 94-96.] Microvascular surgery can also be used to reattach a completely avulsed ear,
[Pennington, D. G., Lai, M. F., & Pelly, A.D. (1980, June). Successful replantation of a completely avulsed ear by microvascular anastomosis. Plastic and Reconstructive Surgery, 65(6), 820-823.][Tanaka, Y., & Tajima, S. (1989, October). Plastic and Reconstructive Surgery, 84(4), 665-668.][Talbi, M., Stussi, J. D., & Meley, M. Microsurgical replantation of a totally amputated ear without venous repair. (2001, August). Journal of Reconstructive Microsurgery, 17(6), 417-420.] but its success rate is lower because of the need for
venous drainage.
[O'Toole, G., Bhatti, K., & Masood, S. (2008). Replantation of an avulsed ear, using a single arterial anastamosis. Journal of Plastic, Reconstructive & Aesthetic Surgery, 61(3), 326-329.] The ear can also be reconstructed with
cartilage and
[Saad Ibrahim, S. M., Zidan, A., & Madani, S. (2008). Totally avulsed ear: New technique of immediate ear reconstruction. Journal of Plastic, Reconstructive & Aesthetic Surgery, 61, S29-36.] or an external ear prosthesis can be made by an
anaplastologist.
Eyelid avulsions
Eyelid avulsions are uncommon,
[Goldberg, S.H., Bullock, J.D., & Connelly, P.J. (1992). Eyelid avulsion: A clinical and experimental study. Ophthalmic Plastic And Reconstructive Surgery, 8(4), 256-261.] but can be caused by motor vehicle collisions,
dog bites,
[Avram, D.R., Hurwitz, J.J., & Kratky, V. (1991, October). Dog and human bites of the eyelid repaired with retrieved autogenous tissue. Canadian Journal of Ophthalmology, 26(6), 334-337.] or human bites.
Eyelid avulsions are repaired by
suturing after a CT scan is performed to determine where damage to the muscles, nerves, and blood vessels of the eyelid has occurred.
[Huerva, V., Mateo, A.J., & Espinet, R. (2008, January). Isolated medial rectus muscle rupture after a traffic accident. Strabismus, 16(1), 33-37.] More severe injuries require reconstruction, however, this usually results in some loss of function and subsequent surgeries may be necessary to improve structure and function.
[deSousa, J.L., Leibovitch, I., Malhotra, R., O'Donnell, B., Sullivan, T., & Selva, D. (2007, December). Techniques and outcomes of total upper and lower eyelid reconstruction. Archives of Ophthalmology, 125(12), 1601-1609.] Microvascular surgery is another method of repair but is rarely used to treat eye avulsions.
[Soueid, N.E., & Khoobehi, K. (2006, January). Microsurgical replantation of total upper eyelid avulsion. Annals of Plastic Surgery, 56(1), 99-102.] Sometimes botulinum toxin is injected into the eyelid to paralyze the muscles while the eyelid heals.
Nail avulsions
Trauma to the nail can cause the nail plate to be torn from the nail bed.
[ Nail Avulsions] Unlike other types of avulsion, when a nail is lost, it is not typically reattached. Following the loss of the nail, the nail bed forms a germinal layer which hardens as the cells acquire
keratin and becomes a new nail.
[Rischer, C.E., & Easton, T.A. (1995). Focus on human biology (2nd ed.). New York: Harper Collins College Publishers.] Until this layer has formed, the exposed nail bed is highly sensitive, and is typically covered with a non-adherent dressing, as an ordinary dressing will stick to the nail bed and cause pain upon removal.
[National Center for Emergency Medicine Informatics. Nail Off. Retrieved January 16, 2009, from [3] .] In the average person, fingernails require 3 to 6 months to regrow completely, while toenails require 12 to 18 months.
Brachial plexus avulsions
In
brachial plexus avulsions, the brachial plexus (a bundle of nerves that communicates signals between the spine and the arms, shoulders, and hands) is torn from its attachment to the
spinal cord. One common cause of brachial plexus avulsions is when a baby's shoulders rotate in the birth canal during delivery, which causes the brachial plexus to stretch and tear.
[National Institute of Neurological Disorders and Stroke. NINDS Erb-Duchenne and Dejerine-Klumpke Palsies Information Page. Retrieved January 15, 2009, from [4] .] It occurs in 1 to 2 out of every 1,000 births.
[American Academy of Orthopaedic Surgeons. Erb's Palsy (Brachial Plexus Birth Injury). Retrieved January 15, 2009, from [5].] Shoulder trauma during motor vehicle collisions is another common cause of brachial plexus avulsions.
[Binder, D. K., Lu, D. C., & Barbaro, N. M. (2005, October). Multiple root avulsions from the brachial plexus. Neurosurgical Focus, 19(3).] Detachment of the nerves can cause pain and loss of function in the arms, shoulders, and hands.
Neuropathic pain can be treated with medication, but it is only through surgical reattachment or nerve grafts that function can be restored.
For intractable pain, a procedure called dorsal root entry zone (DREZ) lesioning can be effective.
Tooth avulsions
During a
Dental avulsion, a tooth is completely or partially (such that the
dental pulp is exposed) detached from its
Tooth socket. Secondary (permanent) teeth can be replaced and stabilised by a dentist.
[Merck Manual Online. Fractured and Avulsed Teeth. Retrieved January 15, 2009, from [6].] Primary (baby) teeth are not replaced because they tend to become infected and interfere with the growth of the secondary teeth.
A completely avulsed tooth that is replaced within one hour of the injury can be permanently retained.
The long-term retention rate decreases as the time that the tooth is detached increases, and eventually
root resorption makes replacement of the tooth impossible.
To minimize damage to the root, the tooth should be kept in milk or sterile saline while it is outside the mouth.
[Kidd, P. S., Sturt, P. A., & Fultz, J. (2000). Mosby's emergency nursing reference (2nd ed.). St. Louis: Mosby, Inc.]
Periosteal avulsions
During a periosteal avulsion, the
periosteum (a fibrous layer that surrounds a bone) detaches the bone's surface. An example of a periosteal avulsion is an
Alpsa lesion (anterior labral periosteal sleeve avulsion).
Surgical avulsions
An avulsion is sometimes performed surgically to relieve symptoms of a disorder, or to prevent a chronic condition from recurring. Small incision avulsion (also called ambulatory phlebectomy) is used to remove
from the legs in disorders such as chronic venous insufficiency.
[Society for Vascular Surgery. VascularWeb: Chronic Venous Insufficiency. Retrieved January 15, 2009, from [7] .] A nail avulsion is performed to remove all or part of a chronic
ingrown nail.
[American Academy of Orthopaedic Surgeons. Ingrown Toenail. Retrieved January 15, 2009, from [8].] Facial nerve avulsion is used to treat the involuntary twitching involved in
Blepharospasm.
[McCord, C.D. Jr., Coles, W.H., Shore, J.W., Spector, R., & Putnam, J.R. (1984, February). Treatment of essential blepharospasm: Comparison of facial nerve avulsion and eyebrow-eyelid muscle stripping procedure. Archives Of Ophthalmology, 102(2), 266-268.][Grandas, F., Elston, J., Quinn, N., & Marsden, C.D. (1988, June). Blepharospasm: A review of 264 patients. Journal of Neurology, Neurosurgery, and Psychiatry, 51(6), 767-772.] However, it often requires additional surgeries to retain function
and botulinum toxin injections have been shown to be more effective than surgical avulsions in treating benign essential blepharospasm, while causing fewer complications.
See also
External links
