Navigated Osteosynthesis for Unstable Atlas Fractures: Technical Note and Case Series

John D Arena; Yohannes Ghenbot; Samuel B Tomlinson; Connor A Wathen; Andrea L C Schneider; H Isaac Chen; Zarina S Ali; James M Schuster; Dmitriy Petrov

doi:10.1016/j.wneu.2024.11.107

Navigated Osteosynthesis for Unstable Atlas Fractures: Technical Note and Case Series

World Neurosurg. 2024 Nov 26:S1878-8750(24)01971-5. doi: 10.1016/j.wneu.2024.11.107. Online ahead of print.

Authors

John D Arena¹, Yohannes Ghenbot², Samuel B Tomlinson², Connor A Wathen², Andrea L C Schneider³, H Isaac Chen², Zarina S Ali², James M Schuster², Dmitriy Petrov²

Affiliations

¹ Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States. Electronic address: John.arena@pennmedicine.upenn.edu.
² Department of Neurosurgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States.
³ Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States; Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.

PMID: 39608489
DOI: 10.1016/j.wneu.2024.11.107

Abstract

Objective: Fractures of the Atlas are typically considered "stable" or "unstable" based upon integrity of the transverse ligament. Whereas stable Jefferson burst fractures can be treated non-operatively, unstable fractures with disruption of the transverse ligament often require surgical intervention. Atlas osteosynthesis has been proposed as a motion-preserving alternative to atlantoaxial fusion. Intraoperative navigation may facilitate safe placement of C1 instrumentation.

Methods: Cases of unstable atlas fractures treated with navigated osteosynthesis at a single Level I Trauma Center were identified and retrospectively reviewed. Clinical presentation, surgical management and post-operative outcomes were assessed.

Results: Eight patients underwent navigated posterior atlas osteosynthesis for unstable C1 fractures between December 2015 and January 2024. All cases demonstrated injury to the transverse ligament (Dickman Type I [n=1] and Type II [n=7]). Patients were followed with serial radiographs demonstrating preserved alignment, with no significant change in post-operative atlantodental interval at most recent follow-up (+0.2±0.87mm [mean change±SD], p=0.53). Six patients obtained follow-up CT, all of which demonstrated evidence of osseous union across fractures without hardware complication. No patients developed post-operative instability requiring fusion.

Conclusion: Atlas osteosynthesis is an attractive motion-preserving approach to the treatment of unstable atlas fractures, avoiding the morbidity of atlantoaxial fusion. Classically reserved for Jefferson fractures with Dickman Type II transverse ligament injury, atlas osteosynthesis may also be a viable option for Type I transverse ligament injuries. Intraoperative navigation can be particularly useful for screw placement in the setting of traumatically distorted anatomy with lateral mass displacement.

Keywords: Atlas Fracture; C1 Fracture; Cervical Fracture; Jefferson Fracture; Lateral Mass; Navigation; Spine Trauma.