Conservative treatment has been described, but there are no outcome studies in the literature. A few articles demonstrate the diagnosis and show that radiographs alone have a low diagnostic rate and that functional MRI may be able to better quantify instability. A few recent studies elucidate new findings regarding pathoanatomy through the use of finite element analysis. Many articles report on the etiological factors including ligamentous laxity, traumatic injury, syndrome instability, iatrogenic instability, congenital, and inflammatory causes. Any question regarding the inclusion of an article was discussed by 3 authors until an agreement was reached. The full-text screening was performed on the selected articles. All articles were screened by title and abstract and a preliminary decision to include an article was made. Search fields were varied until redundant. The literature search was performed in Mendeley. The purpose of this review article is to summarize the current state of knowledge on upper cervical ligamentous instability. Conventional wisdom advocates for use of bracing and physical therapy with only a subset of patients proceeding to obtain surgical treatment. It can be stratified according to spinal level, functional compromise, and mechanism of instability. The patient died shortly after this study was obtained.Cervical spine instability broadly refers to compromise of the articular congruity. White lines (white line) shows that the body of C1 (red arrow) is displaced anteriorly relative to the remainder The imaginary line connecting the spinolaminar Well in excess of the 3 mm maximum in adults. Of the dens and the posterior surface of the C1 tubercle (blue arrow) that measured 14 mm (black line), Shows a marked increase in the distance between the anterior surface Lateral view of the cervical spine done as a cross-table lateral These injuries are usually treated with some form of surgical fusion of C1 and C2Ītlantoaxial dislocation.C6 ─ retrotracheal space should be Less than half the AP diameter of C3 or C4.C3 and C4 ─ retropharyngeal space should be C2 ─ retropharyngeal space should be Disruption in the smooth curve of the imaginary line connecting the spinolaminar white lines of the vertebral bodies.Neurologic injury occurs from cord compression between the odontoid and posterior arch of C1.Associated fractures of the skull and/or facial bones are common.Anterior atlantoaxial dislocations may be, but are not necessarily, associated with a fracture of the dens (~50% at autopsy).Almost all atlantoaxial dislocations involve forward movement of C1 on C2 posterior dislocation is extremely rare.The pathologic mechanism involves hyperflexion of the neck.Traumatic atlantoaxial subluxation/dislocation usually results from a motor vehicle collision in which an unrestrained occupant’s head strikes the windshield or dashboard.While chronic atlantoaxial dislocations which occur in the above diseases may be severe yet asymptomatic, acute atlantoaxial dislocations are more often symptomatic and can be life-threatening.Secondary to odontoid hypoplasia or aplasia.From laxity of the ligaments and destruction of the articular cartilage.Atlantoaxial subluxation associated with inflammation of adjacent soft tissues of the neck.Due to laxity of the transverse ligament.Non-traumatic conditions associated with increase in the atlantoaxial distance.The spinal canal is typically widest at the level of C2 and should not be less than 18 mm in ins widest AP dimension.Symptoms will be present when the atlas moves far enough forward on the axis to narrow the spinal canal and impinge on the spinal cord.Atlantoaxial instability is defined by an increase in the predentate space of greater then 3 mm in adults and 5 mm in children.The transverse ligament is the primary restraint against atlantoaxial, anteroposterior movement.Forward movement of the atlas on the axis is normally restricted by the transverse ligament.The distance may increase slightly on flexion in children but is usually unchanged between flexion and extension in adults.This space is called by many names: predentate space, predental space, atlantodental distance.Distance between the anterior surface of the dens and the posterior surface of the tubercle of C1 is usually 3 mm or less in adults and 5 mm or less in children.

Cervical spine x ray down's syndrome