MDCT of acute subaxial cervical spine trauma: a mechanism-based approach

Injuries to the spinal column are common and road traffic accidents are the commonest cause. Subaxial cervical spine (C3-C7) trauma encompasses a wide spectrum of osseous and ligamentous injuries, in addition to being frequently associated with neurological injury. Multidetector computed tomography (MDCT) is routinely performed to evaluate acute cervical spine trauma, very often as first-line imaging. MDCT provides an insight into the injury morphology, which in turn reflects the mechanics of injury. This article will review the fundamental biomechanical forces underlying the common subaxial spine injuries and resultant injury patterns or "fingerprints" on MDCT. This systematic and focused analysis enables a more accurate and rapid interpretation of cervical spine CT examinations. Mechanical considerations are important in most clinical and surgical decisions to adequately realign the spine, to prevent neurological deterioration and to facilitate appropriate stabilisation. This review will emphasise the variables on CT that affect the surgical management, as well as imaging "pearls" in differentiating "look-alike" lesions with different surgical implications. It will also enable the radiologist in writing clinically relevant CT reports of cervical spine trauma. Teaching Points • Vertebral bodies and disc bear the axial compression forces, while the ligaments bear the distraction forces.• Compressive forces result in fracture and distractive forces result in ligamentous disruption.• Bilateral facet dislocation is the most severe injury of the flexion-distraction spectrum.• Biomechanics-based CT reading will help to rapidly and accurately identify the entire spectrum of injury.• This approach also helps to differentiate look-alike injuries with different clinical implications.