Flexion-Distraction Injury

Cervical flexion-distraction injuries usually follow high-energy trauma — road traffic collisions, falls and sporting impacts — where the head is thrown violently forwards. The essential problem is a failure of the posterior ligaments and facet joints that normally hold the vertebrae aligned. Depending on the severity, this produces a spectrum: ligament sprains and facet subluxation at the milder end; a unilateral (one-sided) facet dislocation, which often causes nerve-root symptoms; and a bilateral (two-sided) facet dislocation, which markedly narrows the spinal canal and carries a high risk of spinal cord injury. A crucial companion problem is that a disc can be torn and pushed backwards behind the vertebra, which becomes very important when planning treatment.

Assessment begins with a careful neurological examination and high-quality imaging. CT shows the bony injury and the position of the facets precisely, while MRI is essential to look at the ligaments, the spinal cord and — critically — whether there is a disc herniation behind the injured level. Modern practice uses validated systems such as the Subaxial Injury Classification (SLIC) and the AO Spine subaxial classification to grade the injury by its morphology, the state of the ligaments and the neurological picture, and to guide whether surgery is needed. This structured approach helps ensure that decisions are consistent and evidence-based rather than arbitrary.

Treatment depends on the severity, the neurology and the alignment. A dislocation frequently needs to be realigned, either by a carefully performed closed reduction using traction, or during surgery. There is an important safety point here that guides my practice: because a torn disc can be displaced behind the vertebra, an MRI is often obtained before reduction in certain situations to make sure that realigning the spine will not push disc material onto the cord. Unstable injuries — most dislocations and injuries with significant ligament disruption — are then stabilised surgically, from the front, the back, or occasionally both, to hold the spine in a corrected, safe position while it heals. More stable, purely bony or ligamentous injuries without displacement can sometimes be managed in a collar or brace with close monitoring. The right path is chosen individually.

The outlook depends heavily on whether the spinal cord was injured and how severely. Where there is no cord injury, stabilising the spine allows the ligaments and bones to heal in good alignment, and most people recover well over the following months, supported by rehabilitation. Where the cord has been injured, recovery is more variable and a specialist rehabilitation programme is central to the care. Throughout, my aim is prompt, accurate assessment, protection of the spinal cord, and a stabilisation plan tailored to the specific injury.

• —Vaccaro AR, et al. The subaxial cervical spine injury classification (SLIC) system. Spine 2007. (PMID 17906580)
• —Vaccaro AR, et al. AOSpine subaxial cervical spine injury classification system. Eur Spine J 2016. (PMID 25716661)
• —Dvorak MF, et al. Surgical approach to subaxial cervical injuries: evidence-based algorithm based on SLIC. Spine 2007. (PMID 17978665)
• —Aarabi B, et al. Subaxial cervical spine injury classification systems. Neurosurgery 2013. (PMID 23417189)
• —Kwon BK, et al. Subaxial cervical spine trauma. J Am Acad Orthop Surg 2006. (PMID 16467183)
• —Patel AA, et al. Subaxial injury classification (SLIC) system and case examples. Neurosurg Focus 2008. (PMID 18980482)
• —Moore TA, et al. Classification of lower cervical spine injuries. Spine 2006. (PMID 16685235)
• —Hadley MN, et al. Facet fracture-dislocation injuries of the cervical spine. Neurosurgery 1992. (PMID 1584374)
• —Grauer JN, et al. Timing and influence of MRI on management of cervical facet dislocations. J Spinal Disord Tech 2009. (PMID 19342930)
• —Botolin S, et al. Role of pre-reduction MRI in complex cervical fracture-dislocations. Patient Saf Surg 2017. (PMID 28904564)
• —Sharif S, et al. Subaxial cervical spine injuries: WFNS Spine Committee recommendations. Neurospine 2020. (PMID 33401854)
• —Joaquim AF, et al. Subaxial cervical spine trauma: evaluation and surgical decision-making. Global Spine J 2014. (PMID 24494184)