Diagnostic evaluation of delayed flexion-extension radiographs after blunt cervical spine trauma: A prospective study

The value of delayed cervical flexion-extension radiographs after blunt cervical spine trauma remains debated in alert patients with persistent neck pain, normal neurological examination, and normal initial static imaging. At Nantes University Hospital, a dedicated delayed dynamic radiography pathway has been used for more than 20 years. This study reassessed its diagnostic relevance.

Prospective, observational, single-centre study conducted in routine clinical practice between May 2022 and May 2024. Two populations were analyzed: patients referred to the delayed dynamic radiography pathway after blunt cervical trauma (n = 303), and patients who underwent surgery for unstable post-traumatic cervical ligamentous injury diagnosed during the acute emergency department assessment (n = 24). The objectives were to determine whether delayed flexion-extension radiographs identify surgically relevant unstable cervical injuries in alert patients without neurological/radiological abnormalities at initial emergency department assessment, and to describe the clinical and radiological features of surgically treated unstable ligamentous injuries.

Among 303 patients referred to the delayed dynamic radiography pathway, 4 unstable cervical ligamentous injuries were identified. Retrospective review showed that all 4 patients had abnormal initial imaging and/or neurological symptoms, and therefore did not meet the intended low-risk pathway criteria. No unstable cervical ligamentous injury was diagnosed among the 299 other patients referred according to the pathway criteria, i.e. without initial neurological/radiological features suggestive of instability. During the same period, 23 unstable cervical ligamentous injuries were diagnosed in the emergency department and treated surgically. Among all 27 surgically treated patients, initial imaging was abnormal in 25 (92.6%) and neurological impairment was present in 16 (59.3%); all (100%) had either abnormal initial imaging and/or neurological findings.

In alert patients with persistent neck pain, normal neurological examination, and no suspicious abnormality on initial static imaging, delayed flexion-extension radiographs did not identify any surgically relevant injury. Routine use of this pathway should be reconsidered, with initial assessment relying on neurological examination and CT-based evaluation, and dynamic radiographs reserved for cases after specialist evaluation.