The Application of 3D-printed Auto-stable Artificial Vertebral Body in En Bloc Resection and Reconstruction of Thoracolumbar Metastases

Background: Nerve compression symptoms and spinal instability, resulting from spinal metastases, significantly impact the quality of life for patients. A 3D-printed vertebral body is considered an effective approach to reconstruct bone defects following en bloc resection of spinal tumors. The advantage of this method lies in its customized shape and innermost porous structure, which promotes bone ingrowth and leads to reduced postoperative complications.

Objective: The purpose of this study is to assess the effectiveness of 3D-printed auto-stable artificial vertebrae in the en bloc resection and reconstruction of thoracolumbar metastases.

Methods: This study included patients who underwent en bloc resection of thoracolumbar metastases based on the Weinstein-Boriani-Biagini surgical staging system, between January 2019 and April 2021. The patients were divided into two groups: the observation group, which was reconstructed using 3D-printed auto-stable vertebral bodies, and the control group, treated with titanium cages and allograft bone. Evaluation criteria for the patients included assessment of implant subsidence, instrumentation-related complications, VAS score, and Frankel grading of spinal cord injury.

Results: The median follow-up period was 21.8 months (range 12-38 months). Among the patients, 10 received a customized 3D-printed artificial vertebral body, while the remaining 10 received a titanium cage. The observation group showed significantly lower operation time, intraoperative blood loss, and postoperative drainage compared to the control group (P < 0.05). At the final follow-up, the average implant subsidence was 1.8 ± 2.1 mm for the observation group and 5.2 ± 5.1 mm for the control group (P < 0.05). The visual analog scale (VAS) scores were not statistically different between the two groups at preoperative, 24 h, 3 months, and 1 year after the operation (P < 0.05). There were no statistically significant differences in the improvements of spinal cord functions between the two groups.

Conclusion: The utilization of a 3D-printed auto-stable artificial vertebra for reconstruction following en bloc resection of thoracolumbar metastases appears to be a viable and dependable choice. The low occurrence of prosthesis subsidence with 3D-printed prostheses can offer immediate and robust stability.