Reconstruction of the Upper Cervical Spine Using a Personalized 3D Printed Vertebral Body in an Adolescent With Ewing Sarcoma
Study Design. Case report. Objective: To describe a three dimensional (3D) printed axial vertebral body used in upper cervical spine reconstruction after a C2 Ewing sarcoma resection in an adolescent boy. Summary of Background Data. Ewing sarcoma is a malignant musculoskeletal neoplasm with a peak incidence in adolescents. Cervical spine as the primary site of the tumor has been related to a worse prognosis. Tumor resection is particularly challenging in the atlantoaxial region due to complexity of the anatomy, necessity for extensive resection according to oncological principles, and a lack of specialized implants for reconstruction. 3D printing refers to a process where 3D objects are created through successive layering of material under computer control. Although this technology potentially enables accurate fabrication of patient specific orthopedic implants, literature on its utilization in this regard is rare. Methods. A 12 year old boy with a C2 Ewing sarcoma underwent a staged spondylectomy. Wide resection of the posterior elements was first performed. Two weeks later, a high anterior retropharyngeal approach was taken to remove the remains of the C2 vertebra. A customized artificial vertebral body fabricated according to a computer model using titanium alloy powder was inserted to replace the defect between C1 and C3. The microstructure of the implant was optimized for better biomechanical stability and enhanced bone healing. Results. Patient had an uneventful recovery and began to ambulate on postoperative day 7. Adjuvant treatment commenced 3 weeks after the surgery. He was tumor free at the 1 year follow up. Computed tomography studies revealed evidence of implant osseointegration and no subsidence or displacement of the construct. Conclusion. This is a case example on the concept of personalized precision medicine in a surgical setting and demonstrates how 3D printed, patient specific implants may bring individualized solutions to rare problems wherein restoration of the specific anatomy of each patient is a key prognostic factor. Level of Evidence: 5
Spine