Trauma of the upper cervical spine: focus on vertical atlantoaxial dislocation

Abstract

Purpose Traumatic ligament injuries of the craniovertebral junction, either isolated or associated with bone avulsion or fracture, often lead to death. These injuries are rare and underrated but are increasingly seen in emergency departments due to the improvement in initial on-scene management of accidents. Vertical atlantoaxial dislocation (AAD) is a specific lesion that was barely reported. Based on our experience, our goal was to systematically investigate the prevalence and prognosis of traumatic vertical AAD and discuss its management. Methods All cervical CT scans performed at our institution between 2006 and 2010 for cervical trauma in adults were retrospectively reviewed. Based on the measurement of lateral mass index (LMI), defined as the gap between C1 and C2 articular facets, we identified three cases of traumatic vertical AAD in 300 CT scans. Their medical records were investigated.Results The incidence of vertical AAD was 1 % in the exposed population. One case was an isolated vertical AAD and two were associated with a type II odontoid fracture. We report the first case in the literature of unilateral vertical AAD. Two patients died rapidly; the survivor was treated with occipitocervical fixation. Specific maneuvers were used for immobilization and reduction. Conclusions This study found a not insignificant incidence of vertical AAD and a high lethality rate. LMI appears to be a relevant radiological criterion for this diagnosis, for which traction is contraindicated. Associated neurological or vascular damage should be suspected and investigated. In our experience, spinal surgical fixation is required because of major instability.

Traumatic atlantoaxial subluxation, posterior transfacet fixation: a case report

“…1,2,8 C1-C2 luxations are rare in adults, occurring in <1% of all spinal injuries and around 20% of lesions of the cervical spine. 1,3,9,10 Atlantoaxial subluxation is rare, and even more so without fracture of the dens (odontoid process) of the axis. As a result, it can sometimes be overlooked.…”

“…12 The pattern of injury is consistent with a mechanism of high-degree hyperextension. 4 The diagnosis is generally difficult; the clinical manifestations are usually rare, such as suboccipital pain on axial pressure on the skull, and on moving the skull the patient spontaneously stiffens the neck, contracting the sternocleidomastoid and trapezius muscles, with dysphagia and pain on anterior palpation of the neck 3,8 , torticollis, and occipital neuralgia. Symptoms of vertebrobasilar insufficiency may sometimes be present.…”

“…Where there is suspicion, imaging studies, plain AP and lateral radiography should be carried out, with their respective measurements, and even more importantly, computed axial tomography with 3D reconstruction. 1,[3][4][5]9,13 Early diagnosis is essential, as a longer period between the lesion and its reduction is correlated with higher rates of recurrence and failure of the reduction through non-surgical techniques 14 We believe that simple radiographic measurements (ADI and Powers Index) of the cervical spine can help in the interpretation of anomalies in segment C1/C2, as in this case, where both measurements showed values compatible with C1/C2 disassociation, as well as helping the team of the emergency unit avoid overlooking these potentially devastating entities.…”

“…These confounding variables include: multiple associated injuries, lack of appropriate imaging studies, and low clinical suspicion due to a lack of specific symptoms. 1,[3][4][5] Injuries in 30% of cases may be combined, atlantoaxial and occipitocervical, with high mortality rates. 1 There are reports of patients with cervical injury without neurological deficit, in which delayed diagnosis and initial stabilization lead to a worse prognosis for the patient in the short to medium terms.…”

Ventral decompression techniques in patients with traumatic and non-traumatic atlanto-axial dislocations

“…Дальнейшее смещение атланта на этом фоне называется атланто-аксиальной дислокацией (ААД). Она бывает 5 видов в зависимости от вектора смещения: передняя, задняя, латеральная, ротационная и вертикальная [3][4][5]. Возможна комбинация этих вариантов, например латеральная и ротационная или передняя и вертикальная [6,7].…”