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Atlas Fracture (C1 Fracture)

advanced
6 min
28 marks
6 questions
Clinical Scenario
A 28-year-old man presents after diving into a shallow pool and striking his head on the bottom. He has severe upper neck pain and is holding his head with his hands. He is neurologically intact. CT scan shows a burst fracture of C1 with bilateral lateral mass displacement. Open-mouth odontoid view shows combined lateral mass displacement of 8mm.
Axial and coronal CT images demonstrating a Jefferson burst fracture of C1 with bilateral anterior and posterior arch fractures. There is lateral displacement of the C1 lateral masses with a combined lateral mass displacement (LMD) of 8mm measured on open-mouth odontoid view. The transverse ligament status is concerning. This represents an unstable C1 ring fracture.
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Axial and coronal CT images demonstrating a Jefferson burst fracture of C1 with bilateral anterior and posterior arch fractures. There is lateral displacement of the C1 lateral masses with a combined lateral mass displacement (LMD) of 8mm measured on open-mouth odontoid view. The transverse ligament status is concerning. This represents an unstable C1 ring fracture.

Image source: Open Access medical literature (NIH/PubMed Central) • CC-BY License

Questions

Question 1 (4 marks)

Describe the CT findings and classify this fracture.

Question 2 (5 marks)

What is the transverse ligament and why is its integrity critical?

Question 3 (6 marks)

How do you assess transverse ligament integrity and what is the Rule of Spence?

Question 4 (5 marks)

What are the treatment options based on stability assessment?

Question 5 (4 marks)

Describe the surgical options when surgery is indicated.

Question 6 (4 marks)

What are the expected outcomes and potential complications?

Exam Day Cheat Sheet

Must Mention

  • •Jefferson = 4-part burst fracture (anterior + posterior arches bilateral)
  • •Transverse ligament integrity = KEY
  • •Rule of Spence: LMD >6.9mm (limited by magnification)
  • •MRI = gold standard for TL assessment
  • •TL intact = collar/halo (8-12 weeks)
  • •TL ruptured = C1-C2 posterior fusion
  • •Usually neurologically intact (wide canal)

Common Pitfalls

  • •Ignoring TL status
  • •Rule of Spence only
  • •No MRI
  • •Surgery for all
  • •Missing vertebral artery
  • •Wrong fusion levels