E³ 819 - Spinal trauma
1. To understand the different standard clinical criteria for spine imaging (Canadian C-spine rule, Nexus criteria).
2. To understand the essential traumatic spinal mechanisms.
3. To become familiar with the different classification systems, from Denis to TLICS.
In trauma patients, the spine is often involved with the thoracolumbar spine as the most common portion, especially T11-L2. The necessity of a radiography after trauma may be weighed with the help of the national emergency x-radiography use study (NEXUS) criteria and the Canadian C-spine rule (CCR). According to the clinical NEXUS criteria, the probability of absence of a fracture is 99.6% in patients with no posterior midline cervical-spine tenderness, no evidence of intoxication, a normal level of alertness, no focal neurologic deficit and no painful distracting injuries. The CCR defines clinical criteria for a low-risk patient for C-spine fractures after blunt trauma with a 100% sensitivity. Comparing the CCR with the NEXUS criteria, CCR performed somehow better. If imaging is indicated by clinical criteria (NEXUS, CCR) the American College of Radiology (ACR) Appropriateness Criteria list the precise indications of imaging modalities (x-ray, CT, MRI, myelography, angiography). Concerning thoracolumbar spinal fractures, the Magerl classification (exclusively applicable for assessment of CT findings) is used which is based on the three-column concept by Denis and the McAfee classification. The Magerl AO concept differentiates between compression (type A), distraction (type B) and rotation (type C). The thoracolumbar injury classification and severity (TLICS) scale is a guideline for management of treatment regarding thoracolumbar injuries. Based on the three major categories (injury morphology, posterior ligamentous complex integrity and patient neurology) patient scores determine a management plan for surgeons depending on the presence of injuries and co-morbidities.
1. To understand which soft tissue structures are relevant for spinal stability.
2. To learn how to detect subtle soft tissue injuries.
3. To become familiar with the different traumatic cord injuries.
In spinal trauma, MRI is the modality of choice for evaluation of ligamentous and other soft tissue structures, disc, spinal cord and vessels. Complete spinal ligamentous tears appear as interruption of those structures normally appearing as low signal intensity bands. It is best depicted on T2-weighted and STIR images. Spinal instability is defined by the involvement of two of the three vertical parallel columns biomechanically forming the vertebral column. Acute disk herniation can also occur and may worsen the symptoms. Neurological deficits may be due to cord compression by epidural or subdural haematoma, or intrinsic spinal cord injury. Axial gradient echo T2-WI is mandatory to identify such haemorrhagic lesions, especially within the cord, because haemorrhagic contusions and haematomyelia are correlated to worse outcome. They appear hypointense while cord oedema returns T2 hyperintensity. Spinal cord trauma usually demonstrates a mixture of both oedema and haemorrhage. In cervical spinal trauma, vascular injuries should be sought as asymptomatic injuries can subsequently lead to cerebral and cerebellar infarctions. Vertebral arteries are more commonly involved than carotid arteries. Main cervical traumas at risk for vascular injuries include C1-C3 fractures, fracture extending into a foramen transversarium, cervical spine luxation and expanding neck haematoma. Most of the vascular injuries can be seen as irregularity or loss of normal flow void on T2WI, and should be confirmed by adequate and dedicated vascular imaging.
1. To understand that children are prone to different types and locations of injuries when compared to adults.
2. To become familiar with normal anatomy and anatomic variants that may mimic fractures in children.
3. To learn how to select the appropriate imaging modality in the individual patient.
Spinal injuries are generally less common in the paediatric population compared to adults with cervical spine injuries being most frequent spine injury of all spine injuries occurring in up to 40-60% of all injuries in children. The specific biomechanics of the paediatric cervical spine leads to a different distribution of injuries and distinct radiological features and represent a distinct clinical entity compared to those seen in adults. Young children have a propensity for injuries to the CCJ, upper cervical injuries (i.e. cranial base to C2) whereas older children are prone to lower cervical injuries similar to those seen in adults. In this lecture, typical injuries in the paediatric population will be presented including normal variants that can be misleading in the diagnosis of fractures.