Fig. 1

a Pre-operatively lateral X-ray; b Anterior view of the computer-aided design model of 3DPLC; c Anterior view of the manufactured 3DPLC based on 1b on a 3D-printed model; d Lateral view of the manufactured 3DPLC based on 1b on a 3D-printed model; e Intra-operative view of the 2 3DPLC before closure; f Anteroposterior X-ray 1 week after the surgery; g Lateral X-ray 1 week after the surgery; h Left sagittal reconstruction of CT of the cervical spine 12 months post-operatively; i Coronal reconstruction of CT of the cervical spine 12 months post-operatively; j Axial CT of the cervical spine 12 months post-operatively; k Right sagittal reconstruction of CT of the cervical spine 12 months post-operatively; l Lateral X-ray 18 months after the surgery