Injury Mechanism of Brachial Plexus edit
Injury to the brachial plexus can happen in numerous environments. These may include contact sports, motor vehicle accidents and birth [1]. Although these are but a common few events, there is one of two mechanisms of injury that remain constant during the point of injury. The two mechanisms that can occur are traction and heavy impact [2]. These two methods disturb the nerves of the brachial plexus and cause the injury [3] .
Traction edit
Traction occurs from severe movement and causes a pull or tension among the nerves. There are two types of traction: downward traction and upward traction. In downward traction there is tension of the arm which forces the angle of the neck and shoulder to become broader. This tension is forced and can cause lesions of the upper roots and trunk of the nerves of the brachial plexus. Upward traction also results in the broadening of the neck and shoulder angle but this time the nerves of T1 and C8 are torn away [4].
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Traction, also known as stretch injury, is one of the mechanisms that cause brachial plexus injury. The nerves of the brachial plexus are damaged due to the forced pull by the widening of the shoulder and neck. This is a closer look at the traction mechanism at the cervical spine. The arrowed red line represents the stretch of the nerves. Depending on the force, lesions may occur.
Impact edit
Heavy impact to the shoulder is the second common mechanism to causing injury to the brachial plexus. Depending on the severity of the impact, lesions can occur at all nerves in the brachial plexus. The location of impact also affects the severity of the injury and depending on the location the nerves of the brachial plexus may be ruptured or avulsed. Some forms of impact that affect the injury to the brachial plexus are shoulder dislocation, clavicle fractures, hyperextension of the arm and sometimes delivery at birth [5]. During the delivery of a baby, the shoulder of the baby may graze against the pelvic bone of the mother. During this process, the brachial plexus can receive damage resulting in injury. The incidence of this happening at birth is 1 in 1000 [6]. This is very low compared to the other identified brachial plexus injuries [7].
External Links edit
http://emedicine.medscape.com/article/91988-overview http://www.sciencedirect.com/science/article/pii/030384679390030K
- ^ Midha, Rajiv, MD. "Neurosurgery." Epidemiology of Brachial Plexus Injuries in a Multitrauma Po... :. Congress of Neurological Surgeons, June 1997. Web. 29 Jan. 2013.
- ^ Narakas, A.O. "The Treatment of Brachial Plexus Injuries." Link.springer.com. International Orthopaedics, June 1985. Web. 28 Jan. 2013.
- ^ Hems, TE.; Mahmood, F. (2012). "Injuries of the terminal branches of the infraclavicular brachial plexus: patterns of injury, management and outcome". J Bone Joint Surg Br. 94 (6): 799–804. doi:10.1302/0301-620X.94B6.28286. PMID 22628595.
{{cite journal}}: Unknown parameter|month=ignored (help) - ^ Coene, L.N.J.E.M. "Mechanisms of Brachial Plexus Lesions." ScienceDirect.com. Clinical Neurology and Neurosurgery, 25 Mar. 2003. Web. 29 Jan. 2013.
- ^ Jeyaseelan, L.; Singh, VK.; Ghosh, S.; Sinisi, M.; Fox, M. (2013). "Iatropathic brachial plexus injury: A complication of delayed fixation of clavicle fractures". Bone Joint J. 95-B (1): 106–10. doi:10.1302/0301-620X.95B1.29625. PMID 23307682.
{{cite journal}}: Unknown parameter|month=ignored (help) - ^ Joyner, Benny, Mary Ann Soto, and Henry M. Adam. "Brachial Plexus Injury." Brachial Plexus Injury. Pediatrics in Review, 1 June 2006. Web. 29 Jan. 2013.
- ^ Midha, Rajiv, MD. "Neurosurgery." Epidemiology of Brachial Plexus Injuries in a Multitrauma Po... :. Congress of Neurological Surgeons, June 1997. Web. 29 Jan. 2013.