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Hu, et al.
manufactured under an accurate computer-assisted with porous structure, which is conducive to bone
digital model [24] , there are inevitably clinical factors ingrowth and fusion (Figure 3); and (v) The 3D-printed
which preclude it from matching with the bone defect. spinal prosthesis side near the spinal dura is designed to
First, tumors cause an extensive and significant be smooth, while the other side is rough. In addition, if
anatomic abnormality of the spine, therefore even there is a spinal pathological fracture or malformation,
after tumor resection, the spine structure can be very it remains difficult to precisely reconstruct the height
difficult to correct to our estimated anatomic position. and curvature of the spine via CT scan parameters.
Secondly, it takes time to manufacture a 3D-printed Therefore, two-stage operations are sometimes needed,
prosthesis after the imaging data acquisition. Some with 3D-printed spinal implant surgery to be performed
highly aggressive spinal tumors may rapidly grow and in the second operation (Case 5).
invade the spine during the waiting time. 3D-printed
spinal implant reconstruction offers many advantages 5. Conclusion
but also comes with uncertainties due to its novel It is clear that 3D-printed spinal implants will continue to
nature. Our experience with these cases demonstrates advance spinal surgery to a new level in the next decade .
[27]
the importance of having a good backup plan, including Our present study demonstrated that when combined
having modular prostheses with multiple options and with tumor comprehensive treatment, 3D-printed
sizes to be used with conventional spinal reconstruction spinal implant surgery provides patients with excellent
techniques.
Although utilizing 3D-printing implants may long-term spinal function and low risk of local tumor
improve spinal reconstructive surgery , we must keep recurrence. Future directions may show further promise
[25]
with modifications of the surface of the 3D-printed spinal
in mind that surgery is a local therapy, which must be
supported with suitable systematic therapy such as implants to allow for enhanced osteogenic effects and
[28,29]
chemo-radiotherapy and targeted medications. Our study anti-tumor activity .
demonstrated that neoadjuvant and adjuvant therapies Funding
combined with 3D-printed spinal implant surgery
provides satisfactory control for recurrent spinal tumors. This work was supported by the National Natural
Zhuang et al. indicated that 3D-printed spinal implant Science Foundation of China (Grant number: 81872179;
[26]
surgery combined with robotic radiotherapy could be a Recipient: Wangjun Yan).
new treatment paradigm for spinal tumors. In our study,
a patient (Case 5) underwent intraoperative radiation. Conflict of Interest
More trials combining neoadjuvant and adjuvant tumor All authors declared that they have no competing interests.
therapies with 3D-printed spinal implant surgery are
being explored in our institution. Author Contributions
Compared to conventional spinal construction, our
3D-printed spinal implant has the following custom- X.H. collected and analyzed the data and drafted the
made features: (i) Accurate vertebral height with multiple manuscript. S.K. critically revised the manuscript. M.C. and
alternative options. According to the CT reconstruction W.C. participated in the surgery. W.H. and W.Y. participated
result, 3D-printed artificial vertebral bodies with three in the surgery, designed the study, and revised the manuscript.
different heights were designed and produced: The All authors read and approved the final manuscript.
standard height, the standard height +3 mm and −3 mm. References
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