Atlanto-occipital dislocation-A challenge with respect to making the diagnosis and treatment

Abstract

The correct diagnosis and treatment of the atlanto-occipital dislocation (AOD) remains amajor challenge. To evaluate the different radiological diagnostic criteria for AOD and discuss potential treatment strategies based on acase with AOD and additional fracture of the atlas. A29-year-old male patient is presented who suffered from AOD with concomitant fracture of the anterior and posterior arches of the atlas with rotational atlantoaxial dislocation following an accident in forestry. The following parameters were evaluated for the diagnosis and assessment of postoperative reduction: Powers ratio, the X‑lines-method, Wackenheim line, basion-dens interval (BDI), basion-axial interval (BAI) and occipital condyle-C1 interval (CCI). Stabilization was performed by occipitocervical spondylodesis from C0 to C2/3. For final reduction it was necessary to reduce the malrotation of the atlas. In the presented case, the revised CCI proved to be asensitive and valid yet practical parameter. Powers' ratio and the BDI were less suited for assessing the diagnosis. The X‑lines-method, Wackenheim line and the BAI did not adequately detect the pathological situation. The AOD is asevere injury requiring immediate correct diagnosis for later adequate treatment results. Among the published parameters, the revised CCI proved to be apractical and valid parameter to detect AOD. For definitive treatment, the operative occipitocervical stabilization is regarded as the method of choice.