The accuracy of a method for printing three-dimensional spinal models.
BACKGROUND
To study the morphology of the human spine and new spinal fixation methods, scientists require cadaveric specimens, which are dependent on donation. However, in most countries, the number of people willing to donate their body is low. A 3D printed model could be an alternative method for morphology research, but the accuracy of the morphology of a 3D printed model has not been determined.


METHODS
Forty-five computed tomography (CT) scans of cervical, thoracic and lumbar spines were obtained, and 44 parameters of the cervical spine, 120 parameters of the thoracic spine, and 50 parameters of the lumbar spine were measured. The CT scan data in DICOM format were imported into Mimics software v10.01 for 3D reconstruction, and the data were saved in .STL format and imported to Cura software. After a 3D digital model was formed, it was saved in Gcode format and exported to a 3D printer for printing. After the 3D printed models were obtained, the above-referenced parameters were measured again.


RESULTS
Paired t-tests were used to determine the significance, set to P<0.05, of all parameter data from the radiographic images and 3D printed models. Furthermore, 88.6% of all parameters of the cervical spine, 90% of all parameters of the thoracic spine, and 94% of all parameters of the lumbar spine had Intraclass Correlation Coefficient (ICC) values >0.800. The other ICC values were <0.800 and >0.600; none were <0.600.


CONCLUSIONS
In this study, we provide a protocol for printing accurate 3D spinal models for surgeons and researchers. The resulting 3D printed model is inexpensive and easily obtained for spinal fixation research.
Department of Orthopaedics, Second Affiliated Hospital of Wenzhou Medical University, Zhejiang Spinal Research Center, 109# Xue Yuan Western Road, Wenzhou, Zhejiang, People's Republic of China.
Ai-Min
AM
Wu
Department of Orthopaedics, Second Affiliated Hospital of Wenzhou Medical University, Zhejiang Spinal Research Center, 109# Xue Yuan Western Road, Wenzhou, Zhejiang, People's Republic of China.
Zhen-Xuan
ZX
Shao
Department of Orthopaedics, Second Affiliated Hospital of Wenzhou Medical University, Zhejiang Spinal Research Center, 109# Xue Yuan Western Road, Wenzhou, Zhejiang, People's Republic of China.
Jian-Shun
JS
Wang
Department of Anatomy, Wenzhou Medical University, Higher Education Zone, Wenzhou, Zhejiang, People's Republic of China.
Xin-Dong
XD
Yang
Department of Orthopaedics, Second Affiliated Hospital of Wenzhou Medical University, Zhejiang Spinal Research Center, 109# Xue Yuan Western Road, Wenzhou, Zhejiang, People's Republic of China.
Wan-Qing
WQ
Weng
Department of Orthopaedics, Second Affiliated Hospital of Wenzhou Medical University, Zhejiang Spinal Research Center, 109# Xue Yuan Western Road, Wenzhou, Zhejiang, People's Republic of China.
Xiang-Yang
XY
Wang
Department of Orthopaedics, Second Affiliated Hospital of Wenzhou Medical University, Zhejiang Spinal Research Center, 109# Xue Yuan Western Road, Wenzhou, Zhejiang, People's Republic of China.
Hua-Zi
HZ
Xu
Department of Orthopaedics, Second Affiliated Hospital of Wenzhou Medical University, Zhejiang Spinal Research Center, 109# Xue Yuan Western Road, Wenzhou, Zhejiang, People's Republic of China.
Yong-Long
YL
Chi
Department of Orthopaedics, Second Affiliated Hospital of Wenzhou Medical University, Zhejiang Spinal Research Center, 109# Xue Yuan Western Road, Wenzhou, Zhejiang, People's Republic of China.
Zhong-Ke
ZK
Lin
D000328:Adult; D002574:Cervical Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006801:Humans; D021621:Imaging, Three-Dimensional; D008159:Lumbar Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D008875:Middle Aged; D008953:Models, Anatomic; D066330:Printing, Three-Dimensional; D013131:Spine / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D013904:Thoracic Vertebrae / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed