spine
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.
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