An 18-year-old female was involved in a motor vehicle crash. The patient's vehicle was broadsided on the driver's side by another car being driven by an impaired driver. Extrication time of the patient was extended and she was unconscious at the scene of the accident. The patient was transported by helicopter to a Level 1 Trauma centre where she was assessed by the Trauma team.
Initial assessment revealed a Glasgow coma scale of 3, and bradycardia. Blood pressure was stable at 100/60 mmHg. Investigations included cervical, thoracic and lumbar spine plain x-ray series, CT examination of the head, chest x-ray and pelvis x-ray. Cervical spine x-rays were interpreted as abnormal in the upper cervical region (Figure 1) , CT of the head revealed diffuse cerebral oedema with evidence of intracerebral shear injury. The remaining radiological investigations were interpreted as normal. The patient had been intubated by the emergency medical technicians prior to transport and following initial assessment the patient was neuromuscularly blocked to assist in the positive pressure ventilation. No active motion had been noted at the emergency scene or during the assessment in the trauma room. Following her trauma workup and resuscitation, the patient was transferred to the intensive care unit for management of her airway and closed head injury. The spine service was consulted for management of the cervical injury. A cervical collar remained on the patient throughout here assessment and resuscitation.
On review of the CT of the cranial-cervical junction (Figure 2) and plain film images, a diagnosis of occipital cervical dissociation was made. The primary decision-making issue was dependent upon the expected prognosis of this individual in regards to the severe brain injury. No assessment of the neurological status of the spinal cord could be accurately made. The occipital-cervical junction was poorly immobilized with the external collar and a decision was necessary as to the potential benefit of proceeding with a stabilization of the injury. The neurosurgical opinion in regards to the recovery of brain function was guarded.
MRI was performed of the brain and cervicomedullary junction of the spinal cord (Figure 3). There was injury of the ligamentous structures of the occipital-cervical junction; however, the cord did not show evidence of increased signal intensity on T2 weighted images indicating cord oedema or injury. Brain images confirmed diffuse axonal brain injury of a severe degree.
The lack of signal change in the cervical cord was encouraging, implying the possible maintenance of integrity and function of the cord. After discussion with the family, the neurosurgical service and the intensive care unit staff, it was felt that posterior fixation of the occipital cervical junction would provide the best care for this individual. Nursing care could be facilitated with low risk to the cervical spine. The patient could be positioned sitting, and if cerebral function improved, the spinal cord at this level would have been protected from possible injury during the acute phase of care of the patient.
The patient was taken to the operating theatre on an urgent basis following the decision to proceed with stabilization. Following placement of Mayfield tongs on the skull, the patient was turned prone onto bolsters and had the head and neck immobilized in the Mayfield extension frame. A check x-ray was obtained to confirm reduction of the occipital-cervical junction. Slight distraction was noted and the bed was placed in a slight head down position to allow some compression at the occipital-cervical junction. A repeat x-ray confirmed reduction of the injury.
Following prepping and draping of the posterior occipital-cervical region as well as the iliac crest a midline incision was performed and exposure of the occiput, inion, arch of C1 and posterior elements of C2 and C3 was performed. Lateral mass plates were contoured to the curve of the craniocervical junction and 3.5mm cancellous screws were placed through the plate into the occiput bilaterally. Further screws were then placed into the pedicle of C2 and laterally into the facet masses of C3. Decortication was performed. A posterior fusion was then performed by placing autologous iliac crest bone graft from the iliac crest spanning the occiput to the posterior elements of C2 and C3. (Figure 4)
Post-operatively, the patient was returned to a semirigid collar and returned to the intensive care unit. The patient remained in intensive care for 8 days postoperatively and had a tracheotomy performed. She was the transferred to the Neurological intensive care unit and was gradually mobilized with the aid of the spinal rehabilitation therapists. The patient's level of consciousness improved gradually and she started to respond to verbal commands and voices a four weeks following her injury.
Following her acute care, this patient was transferred to the brain injury rehab service. Recovery of neurological function was progressive and at 3 months following her injury, the patient began standing with the aid of a walker. Her speech and responsiveness improved rapidly and she was able to carry on conversations with her caregivers and family.
At eight months following her injury the patient's residual neurological deficit consisted of a left-sided hemiplegia as a result of the closed head injury. She is currently an independent ambulator and has returned to school to complete her studies that were abruptly halted by the accident. She has no neck symptoms and a repeat MRI reveals a normal spinal cord at the cervical-medullary junction.(Figure 5)
Occipital cervical dissociation or dislocation is rare in the surviving trauma patient. These injuries are usually associated with high cervical cord injury followed by death. The injury is highly unstable. In our case, radiographs taken one hour apart in the intensive care unit show evidence of translation of the cranium on the atlas of 3-4 mm as a result of changes in positioning while lying supine in bed with a collar "immobilizing" the spine. A stabilization procedure is necessary and should be done on an urgent basis to prevent further injury to the neurological structures of the craniocervical junction. In our patient, the closed head injury confounded our ability to assess the neurological status of the cord as well as the ultimate prognosis of the individual. In these circumstances, an aggressive approach is warranted provided the patient has haemodynamic and pulmonary system stability.
Stabilization consisting of occipital cervical plating provided optimal stability and early mobilization of the patient. Fusion provided permanent stability.
Figure 1: Lateral cervical spine x-ray demonstrating gap between the occipital condyles and the superior articular surface of the atlas.
Figure 2: Sagital and coronal reconstructions of CT of occipital cervical junction. Note the non-conguity of the joint and the subluxation of the occiput anteriorly.
Figure 3: Sagital MRI of upper cervical spine.
Figure 4: Lateral cervical spine x-ray demonstrating stabilization of the occipital-cervical junction and prescence of bone fusion posteriorly spanning the construct. Reduction of occipital condyles is noted.
Figure 5: Sagital MRI 10 months post injury demonstrating normal cord signals in cervicomedullary junction.