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Diagnostic Work-Up and Treatment of Traumatic Spondylolisthesis of the Axis: Case Series and Literature Review

Introduction Traumatic spondylolisthesis of the axis represents a spectrum of injuries affecting the C2-C3 level, secondary to bilateral fracture of the pars of C2 due to extension and/or compression forces. The integrity of the C2-C3 disc and the posterior longitudinal ligament are key elements for segmental stability and should be thoroughly assessed before deciding the treatment modality. The aim of this study is to describe the diagnostic work-up and treatment decision in a case series of patients with traumatic spondylolisthesis of the axis. We also present a review of the available literature about this type of injuries. Material and Methods We reviewed the medical records and images of patients with a traumatic spondylolisthesis of the axis treated in two centers between January 2008 and March 2015. Details regarding demographics, injury mechanism, type of lesion (using the Levine & Edwards classification) and treatment modality (surgical or non-surgical and its justification) were analyzed. We also performed a literature review, focusing on the diagnosis and treatment of these injuries. Results Case series including 7 patients (4 males, mean age at the time of the injury of 37.9 years [23–55]). Six patients (85.7%) were injured in a motor vehicle accident and 28.6% (2/7) presented other spine fractures. All of the patients were neurologically intact. Five cases (71.4%) had a type I injury. Magnetic resonance imaging was obtained as part of the initial assessment in 5 patients (71.4%), none of these patients were considered to have a disrupted posterior longitudinal ligament, while 2 (28.6%) presented hyper intensity at the C2-C3 disc on T2-weigthed images. Surgery was promptly indicated only in one case (type III lesion with a disrupted C2-C3 disc on magnetic resonance imaging, in which an instrumented posterior C2-C3 fusion was performed). The remaining 6 patients (85.7%) were originally treated non-surgically with a hard collar, but 2 of them (both with type I injuries) had surgery one week after the accident (one anterior and one posterior instrumented C2-C3 fusion) due to progressive listhesis and angulation at the C2-C3 level. No treatment-related complications were identified in both surgically and non-surgically treated patients. The available literature emphasizes the importance of the assessment of the C2-C3 disc and the posterior longitudinal ligament via magnetic resonance imaging before deciding the treatment modality in these patients. Conclusion Initial imaging work-up, particularly regarding the C2-C3 disc and posterior longitudinal ligament's integrity on magnetic resonance imaging, together with close radiological follow-up are key elements to consider in the treatment of traumatic spondylolisthesis of the axis.