We need you! See something you could improve? Make an edit and help improve WikSM for everyone.


From WikiSM
Jump to: navigation, search

Other Names

  • Physiologic anterior spondylolisthesis


  • This page describes 'pseudosubluxation', a physiological or normal anterior spondylolisthesis of the cervical spine seen in young children



  • Approximately 20% of children admitted for polytrauma will demonstrate this finding[1]
  • Typically seen in children under age 8
  • C2 on C3 #1 seen in 25% of children, C3 on C4 #2 in 15% (need citation)
  • Rarely seen in adults[2]


  • In young children, the vertebral facets are nearly horizontal, which gives them more mobility
    • They become more vertical with age
  • Anterior spondylolisthesis typically of C2 on C3

Risk Factors

  • Age <8

Differential Diagnosis

Clinical Features

  • General: Physical Exam Neck
  • History
    • Typically discovered following trauma
  • Physical Exam
  • Special Tests



  • Standard Cervical Spine Radiographs
    • Lateral view: anterior displacement of C2 vertebral body relative to C3
  • Flexion Extension Cervical Spine Radiographs
    • Up to 46% of normal children under 8 have 3 mm of motion of C2 on C3, 14% of C3 on C4[3]
    • Subluxation should exaggerated with flexion and reduce on extension
    • Absence of soft tissue swelling
  • Swischuk's line
    • Drawn from spinolaminar point on C1 to C3, should be within 2 mm of anterior cortex


  • Similar findings to radiographs
  • More helpful to exclude fractures or other osseous injuries


  • Useful for evaluating soft tissue injuries


  • N/A



  • Excellent


  • By definition, non surgical

Rehab and Return to Play


  • Needs to be updated

Return to Play

  • Needs to be updated


  • Generally none

See Also


  1. Shaw M, Burnett H, Wilson A, Chan O. Pseudosubluxation of C2 on C3 in polytraumatized children – prevalence and significance. Clin Radiol. 1999;54(6):377–80.
  2. Curtin P, McElwain J. Assessment of the “nearly normal” cervical spine radiograph: C2–C3 pseudosubluxation in an adult with whiplash injury. Emerg Med J. 2005;22(12):907–8.
  3. Cattell HS, Filtzer DL (1965) Pseudosubluxation and other normal variations in the cervical spine in children. A study of one hundred and sixty children. J Bone Joint Surg Am 47:1295–1309
Created by:
John Kiel on 3 May 2020 22:40:39
Last edited:
6 October 2022 23:17:11