3D-printed vertebral body for anterior spinal reconstruction in patients with thoracolumbar spinal tumors

OBJECTIVE A 3D-printed vertebral prosthesis can be used to reconstruct a bone defect more precisely because of its tailored shape, with its innermost porous structure inducing bone ingrowth. The aim of this study was to evaluate the clinical outcomes of using a 3D-printed artificial vertebral body for spinal reconstruction after en bloc resection of thoracolumbar tumors. METHODS This was a retrospective analysis of 23 consecutive patients who underwent surgical treatment for thoraco-lumbar tumors at our hospital. En bloc resection was performed in all cases, based on the Weinstein-Boriani-Biagini sur-gical staging system, and anterior reconstruction was performed using a 3D-printed artificial vertebral body. Prosthesis subsidence, fusion status, and instrumentation-related complications were evaluated. Stability of the anterior reconstruc-tion method was evaluated by CT, and CT Hounsfield unit (HU) values were measured to evaluate fusion status. RESULTS The median follow-up was 37 (range 24-58) months. A customized 3D-printed artificial vertebral body was used in 10 patients, with an off-the-shelf 3D-printed artificial vertebral body used in the other 13 patients. The artificial vertebral body was implanted anteriorly in 5 patients and posteriorly in 18 patients. The overall fusion rate was 87.0%. The average prosthesis subsidence at the final follow-up was 1.60 +/- 1.79 mm. Instrument failure occurred in 2 patients, both of whom had substantial subsidence (8.47 and 3.69 mm, respectively). At 3 months, 6 months, and 1 year post- operatively, the mean CT HU values within the artificial vertebral body were 1930 +/- 294, 1997 +/- 336, and 1994 +/- 257, respectively, with each of these values being significantly higher than the immediate postoperative value of 1744 +/- 321 (p < 0.05). CONCLUSIONS The use of a 3D-printed artificial vertebral body for anterior reconstruction after en bloc resection of the thoracolumbar spinal tumor may be a feasible and reliable option. The low incidence of prosthesis subsidence of 3D-printed endoprostheses can provide good stability instantly. Measurement of HU values with CT is a valuable method to evaluate the osseointegration at the bone-metal interface of a 3D-printed vertebral prosthesis. https://thejns.org/doi/abs/10.3171/2022.1.SPINE21900

Automated summary

This study evaluated the clinical outcomes of using a 3D-printed artificial vertebral body for spinal reconstruction after en bloc resection of thoracolumbar tumors. The results showed that the use of a 3D-printed vertebral prosthesis can provide good stability and osseointegration, making it a feasible and reliable option for anterior reconstruction.