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Role of flexion/extension radiography in neck injuries in adults

Three Part Question

In [a neurologically intact adult patient with neck pain following trauma but normal plain xrays] do [flexion/extension xrays] aid [diagnosis of ligamentous or soft tissue injury with instability]?

Clinical Scenario

A man attends the emergency department having been involved in a high speed road traffic accident. He complains of neck pain and midline neck spinal tenderness but has no neurological signs or symptoms. Standard 3-view cervical spine radiology (lateral, anteroposterior and odontoid views) reveals no abnormality. You wonder if a flexion/extension x-ray would show any significant injury/instability.

Search Strategy

Medline 1966-05/04 and Embase 1980-05/04 using the Ovid interface.
[exp neck injuries/ OR neck OR cervical spine OR exp spinal injuries/ OR exp spinal cord injuries/ Or exp spinal fractures/ OR exp fractures/ OR cervical spine injur$.mp OR exp dislocations/ OR exp cervical vertebrae/ OR cervical spinal cord OR exp spinal cord compression/] AND [flexion-extension.ti OR dynamic cervical spine radiograph$.mp OR flexion-extension radiograph$.mp OR flexion-extension cervical spine radiograph$.mp OR flexion-extension x-ray$.mp] AND [exp joint instability/ OR ligamentous OR ligament OR cervical vertebrae/ OR exp fractures/ OR ligamentous OR exp soft tissue injuries/ OR soft tissue] LIMIT to human AND English.

Search Outcome

Altogether 101 papers were found in Medline and 79 papers in Embase of which 5 were relevant.

Relevant Paper(s)

Author, date and country Patient group Study type (level of evidence) Outcomes Key results Study Weaknesses
Brady WJ et al,
451 patients over age 18 years with blunt trauma undergoing SCSR and FECSRRetrospective descriptive reviewAbnormality on FECSR372 (82.5%) normal SCSR of whom 5 (1.3%) had abnormal FECSR

Patients with blunt trauma and neck complaints & an abnormal SCSR are more likely to have abnormal FECSR showing cervical injury requiring stabilisation than if they had normal SCSR
Retrospective Convenience Sample – referral bias Clinical outcome of patients not really addressed No comment on adequacy of radiographs
Complications of FECSRNo complications from FECSR
Lewis LM et al,
141 consecutive adult trauma patients who had Flexion Extension Cervical Spine Radiography (FECSR) after Static Cervical Spine Radiography SCSR seriesRetrospective reviewRadiological abnormality on SCSR11/141 instability on FECSR of which 4 had normal SCSR. 4 had equivocal SCSR & 3 had fractures on SCSRRetrospective No comment on blinding or not of radiologist If abnormal SCSR, computed tomography (CT) as well as FECSR done but sometimes before FECSR - Not clear if diagnosis made on CT or FECSR Adequacy of x-ray not defined
Instability on FECSRFECSR (compared to SCSR alone) increased the sensitivity and specificity for recognising injury from 71% to 99% and 89% to 93% respectively but this was not statistically significant due to small numbers
Neurological sequelae from performing radiographsNo neurological complications from FECSR
Wang JC et al
290 patients following trauma – with neck pain, alert, neurologically intact had FECSRRetrospetive reviewInstability on FECSR1/290 (0.34%) instability on FECSRRetrospective Assessment of adequacy – qualitative SCSR not mentioned in study
Adequacy of FECSR97/290 (33.45%) FECSR were inadequate and could not be assessed for instability so evaluated clinically later
Neurological problems due to FECSRNo neurological changes during FECSR
Pollack CV Jr et al,
86 patients who had FECSR with radiographically demonstrated cervical spine injury from blunt trauma from NEXUS database (patients also had SCSR & CT/Magnetic Resonance Imaging (MRI) as deemed necessary)Subgroup analysis on prospective observational databaseIncidence of diagnostic FECSR in patients with normal SCSR6/86 had normal SCSR but abnormal FECSR but none of these were deemed to be clinically significantNo statistics performed No comment on adequacy of x-ray Posthoc subgroup analysis CT/MR used – confounding results Small numbers
Insko EK et al,
106 cases aged 17-85, within 12 hours of blunt trauma, evaluated with FECSR - awake, had pain and normal SCSRRetrospective reviewInterpretation and adequacy of CSR x-rays. Clinical outcome on follow up9/106 patients had Cervical Spine Injury (CSI) on basis of x-ray, clinical diagnosis and follow up. 74/106 (70%) had adequate FECSR of which 5 had CSI (No false negatives). 32 (30%) had inadequate FECSR of which 4 (12.5%) had CSI subsequently found on CT or MRIRetrospective No statistics performed Not all patients had the same imaging - varied number & types of plain Xray and CT/MR Excluded 228 patients due to inadequate follow up or Xray taken after 12 hours


Most studies are retrospective so the evidence base is limited. Flexion-extension cervical spine radiography (FECSR) is safe in the properly selected patient. If the patient has adequate movement FECSR rarely adds to investigation if standard cervical spine radiography (SCSR) is normal. FECSR after an abnormal SCSR is of limited value because of the possibility of inadequate studies (because of pain or muscle spasm) and the risk of false negatives.

Clinical Bottom Line

In the acute setting FECSR adds little if CT/MR can be used to seek fractures or ligamentous instability.


  1. Brady WJ, Moghtader J, Cutcher D et al. Ed use of flexion-extension cervical spine radiography in the evaluation of blunt trauma. Am J Emerg Med 1999;17(6):504-8.
  2. Lewis LM, Docherty M, Ruoff BE, et al. Flexion-extension views in the evaluation of cervical spine injuries. Ann Emerg Med 1991;20(2):117-21.
  3. Wang JC, Hatch JD, Sandhu HS, et al. Cervical flexion and extension radiographs in acutely injured patients. Clin Orthop 1999;(365):111-6.
  4. Pollack CV Jr, Hendey GW, Martin DR, et al. Use of flexion-extension radiographs of the cervical spine in blunt trauma. Ann Emerg Med 2001;38(1):8-11.
  5. Insko EK, Gracias VH, Gupta R, et al. Utility of flexion and extension radiographs of the cervical spine in the acute evaluation of blunt trauma. J Trauma 2002;53(3):426-9.