Radiological examination and assessment
All cages during the ACDF procedure were implanted under fluoro X-ray control. The day after surgery, plain radiography of the cervical spine was performed in the lateral and anterior–posterior projection to evaluate the correct position of the cage. There are several measuring methods for evaluation of bony fusion achievement (CT, X-plain, X-flexion/extension), with no existing gold standard. The authors of the present study do not consider X-plain imaging as sufficient for final evaluation of bony fusion, despite this imaging being common in our department.CT examinations were performed on Somatom Definition AS + scanner (Siemens, Erlangen, Germany). The standard protocol includes 2 mm scans in axial, coronal and sagittal planes in the osteo-kernel. Evaluation of radiological data was performed by an independent radiologist (PR)Fusion quality scaleFusion quality grades on CT scans. Grade I—complete fusion: Al