Fig. 2.

Imaging findings for case number 3. (A, B) Preoperative contrast-enhanced sagittal and axial T2-weighted magnetic resonance imaging shows a dumbbell tumor with C6/7 vertebral body involvement. Preoperative biopsy pathology indicated chordoma. (C) The lateral mass (LM) prosthesis was preoperatively designed based on the patient’s computed tomography (CT) data, and (D) the 3D-printed LM prosthesis was manufactured. (E) The first-stage posterior approach was used to remove the intraspinal tumor and reconstruct the LM structure. (F) A coronal CT scan of the reconstruction at 6 postoperative months shows that the LM prosthesis is in a good position. Dynamic radiographs taken in extension (G) and flexion (H) showed the stability of the implant.