What is an AO dislocation?
From Wikipedia, the free encyclopedia. Atlanto-occipital dislocation, orthopedic decapitation, or internal decapitation describes ligamentous separation of the spinal column from the skull base. It is possible for a human to survive such an injury; however, 70% of cases result in immediate death.
What is an atlanto occipital dissociation?
Introduction: Atlanto-occipital dissociation (AOD) is a rare and unstable injury of the craniocervical junction, associated with very high morbidity and mortality. The most common cause of this injury is high energy trauma with hyperextension of the cranium, such as car accidents.
Can you dislocate your head from your spine?
The injury is known in medical terms as atlanto-occipital dislocation (the “atlas” is the name of the topmost vertebral bone of the spine; the “occipital” bone forms the lower part of the back of the skull). The injury is three times more common in children than in adults, according to a 2015 review study.
What is atlanto occipital instability?
Atlanto-axial instability (AAI) is a condition that affects the bones in the upper spine or neck under the base of the skull. The joint between the upper spine and base of the skull is called the atlanto-axial joint. In people with Down syndrome, the ligaments (connections between muscles) are “lax” or floppy.
What is atlantoaxial dislocation?
Atlantoaxial dislocation refers to a loss of stability between the atlas and axis (C1–C2), resulting in loss of normal articulation (Fig. 1). The atlantoaxial joints can lose stable articulation from traumatic, inflammatory, idiopathic, or congenital abnormalities.
What is an occipital fracture?
Occipital condyle fractures are traumatic injuries that involve articulation between the base of the skull and the cervical spine.
What causes atlantoaxial subluxation?
The causes of atlantoaxial subluxation may be multifactorial, including transverse ligament damage by a periodontoidal proliferative pannus or sequelae of ossification of the anterior and posterior longitudinal ligaments, associated inflammatory lesions (cervical spine osteoarthritis, atlantodental synovitis, erosions …
What causes atlantoaxial instability?
Atlantoaxial instability can be caused by many factors. Trauma injury, congenital defects (defects from birth), and arthritis. A commonality among these causes is the possibility and extent of cervical ligament damage.
How are AOD injuries related to the atlanto-occipital joint?
Atlanto-occipital dissociation (AOD) injuries are severe and include both atlanto-occipital dislocations and atlanto-occipital subluxations. The tectorial membrane and alar ligaments provide most of the stability to the atlanto-occipital joint, and injury to these ligaments results in instability due to low inherent osseous stability 3.
What does atlanto occipital dislocation mean in medical terms?
Atlanto-occipital dislocation. Atlanto-occipital dislocation, orthopedic decapitation, or internal decapitation describes ligamentous separation of the spinal column from the skull base.
Can a hangman’s fracture be an atlanto occipital dislocation?
The Hangman’s fracture which is a fracture of the C2 vertebral body or dens of the cervical spine upon which the skull base sits to allow the head to rotate, can also be associated with atlanto-occipital dislocation. Despite its eponym, the fracture is not usually associated with a hanging mechanism of injury.
What happens if you have a displaced atlanto-axial dislocation?
Displaced Fracture or Dislocation of Atlanto-Axial Joint Displaced Atlanto-axial Dislocation1 or Fracture can cause severe spinal cord compression resulting in significant neurological injuries of upper spinal cord and lower medulla oblongata. Patient may suffer paralysis of all 4 extremities ( quadriplegia ).