CAISS Spine Injuries 2 — Questions and Answers
Question 1: In the AIS, a cervical spinal cord injury with complete loss of motor and sensory function below the injury level is coded at which severity level?
- AIS 3
- AIS 4
- AIS 5
- AIS 6 (Correct answer)
Correct answer: AIS 6
Complete spinal cord injuries with neurological deficit are coded AIS 6 (maximum severity) in the Abbreviated Injury Scale.
Question 2: Which AIS body region is used when coding injuries to the thoracic vertebral body without spinal cord involvement?
- Region 1 (Head)
- Region 4 (Abdomen)
- Region 5 (Spine) (Correct answer)
- Region 6 (Extremity)
Correct answer: Region 5 (Spine)
The Spine region (Region 5) encompasses all vertebral column injuries regardless of spinal cord involvement.
Question 3: A patient sustains a fracture-dislocation at C5-C6 with incomplete quadriplegia. What additional descriptor is critical for accurate AIS coding?
- Patient age
- Level of consciousness at scene
- Neurological deficit presence and completeness (Correct answer)
- Time elapsed before imaging
Correct answer: Neurological deficit presence and completeness
Neurological deficit type and completeness (complete vs. incomplete) are essential determinants of the AIS severity score for spinal injuries.
Question 4: According to AIS coding conventions, which of the following lumbar spine injuries would receive the LOWEST severity score?
- L2 burst fracture without neurological deficit
- L3 fracture with cauda equina syndrome
- L1 compression fracture without neurological deficit (Correct answer)
- L4 fracture-dislocation with incomplete paraplegia
Correct answer: L1 compression fracture without neurological deficit
A simple compression fracture of L1 without neurological deficit is a minor mechanical injury coded at a lower AIS severity than fractures with neurological compromise.
Question 5: When calculating Injury Severity Score (ISS) for a patient with an AIS 5 cervical spine injury and AIS 4 chest injury, the ISS calculation includes:
- Only the highest AIS score squared
- Sum of all AIS scores squared
- Sum of squares of the three highest AIS scores from different body regions (Correct answer)
- Sum of squares of all injuries in the same region
Correct answer: Sum of squares of the three highest AIS scores from different body regions
ISS sums the squares of the highest AIS scores from each of the three most severely injured body regions.
Question 6: A spinal cord injury classified as ASIA Impairment Scale grade B corresponds most closely to which AIS coding characteristic?
- Complete injury — AIS 6
- Incomplete injury with sensory preservation below lesion level (Correct answer)
- Injury with no neurological deficit
- Minor vertebral fracture without cord involvement
Correct answer: Incomplete injury with sensory preservation below lesion level
ASIA grade B denotes sensory incomplete injury (sensory preserved but no motor function below level), which maps to incomplete spinal cord injury in AIS coding.
Question 7: Which mechanism of cervical spine injury is most commonly associated with bilateral facet dislocations requiring the highest AIS spine severity codes?
- Hyperextension with axial loading
- Hyperflexion with distraction (Correct answer)
- Lateral bending
- Axial compression alone
Correct answer: Hyperflexion with distraction
Hyperflexion-distraction mechanisms produce bilateral facet dislocations with high instability and frequent complete cord injury, earning the highest AIS severity ratings.
CAISS Spine Injuries 2
In the AIS, a cervical spinal cord injury with complete loss of motor and sensory function below the injury level is coded at which severity level?