Ability of magnetic resonance imaging to accurately determine alar ligament integrity in patients with atlanto-occipital injuries

Abstract

Objective:The objective of this study is to evaluate the the reliability of magnetic resonance imaging (MRI) in diagnosing alar ligament disruption in patients with potential atlanto-occipital dissociation (AOD).Materials and Methods:Three-blinded readers performed retrospective review on 6 patients with intra-operative confirmed atlanto-occipital dissocation in addition to a comparison cohort of patients with other cervical injuries that did not involve the atlanto-occipital articulation. Ligament integrity was graded from 1 to 3 as described by Krakenes et al. The right and left ligaments were assessed separately. Inter-observer agreement by patient, by group (AOD vs. non-AOD), and intra-observer agreement was calculated using weighted Cohen's kappa.Results:Interobserver agreement of alar ligament grade for individual patients ranged from slight to fair (κ = 0.05–0.30). Interobserver agreement of alar ligament grade for each group (AOD vs. non-AOD) ranged from fair to substantial (κ = 0.37–0.66). No statistically significant difference in categorical analysis of groups (AOD vs. non-AOD) and grade (0–1 vs. 2–3) was observed. Intraobserver agreement of individual patient's alar ligament grade ranged from moderate to substantial (κ = 0.50–0.62).Conclusion:The use of MRI to detect upper cervical ligament injuries in AOD is imperfect. Our results show inconsistent and unsatisfactory interobserver and intraobserver reliability in evaluation of alar ligament injuries. While MRI has immense potential for detection of ligamentous injury at the craniovertebral junction, standardized algorithms for its use and interpretation need to be developed.

Tectorial Membrane Injury, Frequently Identified in Adult Trauma Patients Who Undergo Occipital-Cervical Fusion for Craniocervical Instability

“…Secondly, the importance of the alar ligaments in maintaining CCJ stability necessitates direct inspection of these ligaments on all cervical MRI examinations in the acute trauma setting. Given the relatively small size of the alar ligament, anatomic complexity of the CCJ, and potential for motion and artifact degraded imaging in the trauma setting, direct inspection of the alar ligaments may be challenging [ 17 - 19 ]. However, specifically-tailored MRI protocols in the setting of clinical or radiologic suspicion for CCJ injury, including both coronal T2-weighted imaging and multiplanar imaging, may help mitigate these challenges [ 20 , 21 ].…”

Diagnostic Benefit of MRI for Exclusion of Ligamentous Injury in Patients with Lateral Atlantodental Interval Asymmetry at Initial Trauma CT

“…The reliability and benefits of MRI in excluding alar ligament injuries are disputable. With use of intraoperative correlation, Dyas et al (35) revealed that MRI is imperfect in depicting upper cervical ligament injuries in patients with atlanto-occipital dissociation due to inconsistent and unsatisfactory inter-and intraobserver reliability. They concluded that standardized algorithms are needed for the use of MRI and interpretation of MRI findings.…”

Novelties for increased safety in cranio-vertebral surgery: a review

“…Indeed, in the last decades, the gradual technological improvement has been followed by the introduction of novel diagnostic radiological criteria for atlantooccipital dislocation (AOD), as for example the condylar sum (Fig. 1 a–c) [ 4 , 15 ]. Historically, this life-threatening traumatic injury of the CVJ was diagnosed on X-rays or regular CT-scan.…”