Multilevel 3D Printing Implant for Reconstructing Cervical Spine With Metastatic Papillary Thyroid Carcinoma

Study Design. A unique case report. Objective. A three-dimensional (3D) printing technology is proposed for reconstructing multilevel cervical spine (C2-C4) after resection of metastatic papillary thyroid carcinoma in a middle-age female patient. Summary of Background Data. Papillary thyroid carcinoma is a malignant neoplasm with a relatively favorable prognosis. A metastatic lesion in multilevel cervical spine (C2-C4) destroys neurological functions and causes local instability. Radical excision of the metastasis and reconstruction of the cervical vertebrae sequence conforms with therapeutic principles, whereas the special-shaped multilevel upper-cervical spine requires personalized implants. 3D printing is an additive manufacturing technology that produces personalized products by accurately layering material under digital model control via a computer. Reporting of this recent technology for reconstructing multilevel cervical spine (C2-C4) is rare in the literature. Methods. Anterior-posterior surgery was performed in one stage. Radical resection of the metastatic lesion (C2-C4) and thyroid gland, along with insertion of a personalized implant manufactured by 3D printing technology, were performed to rebuild the cervical spine sequences. The porous implant was printed in Ti(6)AL(4)V with perfect physicochemical properties and biological performance, such as biocompatibility and osteogenic activity. Finally, lateral mass screw fixation was performed via a posterior approach. Results. Patient neurological function gradually improved after the surgery. The patient received 11/17 on the Japanese Orthopedic Association scale and ambulated with a personalized skull-neck-thorax orthosis on postoperative day 11. She received radioiodine I-131 therapy. The plane x-rays and computed tomography revealed no implant displacement or subsidence at the 12-month follow-up mark. Conclusion. The presented case substantiates the use of 3D printing technology, which enables the personalization of products to solve unconventional problems in spinal surgery.