Atlantooccipital dislocation in motor vehicle side impact, derivation of the mechanism of injury, and implications for early diagnosis

Abstract

Numerous reports of atlantooccipital dislocations (AODs) have been described in frontal impacts and vehicle versus pedestrian collisions. Reports of survival after AOD in conjunction with side impacts have infrequently been reported in the literature. The objective of this study is to present a case of an AOD from a side impact vehicle collision, and deduce the mechanism of injury. A clinical and biomechanical reconstruction of the collision was performed to investigate the mechanism of the dislocation. A 51-year-old female was traveling in a four-door sedan and sustained a side impact collision with a compact pickup truck. At the time of extrication, the patient was neurologically intact with a Glasgow Coma Scale score of 15. After admittance to the hospital, the patient developed a decline in respiratory status, right mild hemiparesis, and left sixth-nerve palsy, and magnetic resonance imaging (MRI) and computed tomography (CT) reconstructions indicated a craniocervical dislocation. Surgical fixation was performed and all extra-axial hemorrhaging was evacuated. At discharge, the patient was neurologically intact on the left side, had right mild hemiparesis, left sixth-nerve palsy, and minor dysarthria. Survival rates of AODs have recently been increasing. Morbidity is still more prevalent, however. Due to the variety of symptoms that accompany AODs and the inconsistency of diagnostic imaging techniques, a thorough history of the etiology may lead to increased clinical suspicion of this injury and further raise survival rates.

The Application of the Revised Condyle–C1 Interval Method to Diagnose Traumatic Atlanto-occipital Dissociation in Adults

“… 2 3 4 In the recent years, reports indicting favorable outcomes have emerged reflecting improvements in the emergency management, transport, and, most importantly, recognition of this injury. 5 6 7 8 …”

Atlanto-Occipital Dislocation: A Case Report

“…Although AOD may be overtly obvious on plain films with severe dislocation, in survivors the radiographic diagnosis is often more subtle 1314). AOD should be suspected in any patient involved in a high speed motor vehicle or pedestrian collision 12561819). Once suspected, proper imaging and appropriate management of these once fatal injuries can improve survival and neurologic outcome 2610111219)…”

“…AOD is a highly unstable craniocervical injury, resulting from damage to ligaments and/or bony structures connecting the skull to the cervical spine 318). Brainstem and upper cervical spinal cord injury affects significant neurological morbidity and mortality.…”

Unilateral atlanto-axial fractures in near side impact collisions: An under recognized entity in cervical trauma

“…The subjects incurred initial movement toward the side of impact resulting in contact with the structures of the occupant compartment. [ 13 ] Impact of the lateral and frontal calvarium will cause a reversal of the head-neck complex motion with lateral bending toward the side contralateral to the impact [ Figure 2 ]. The complexity of the atlanto-axial complex is responsible for a sequence of events that define load application in these impacts.…”