The application of 3D printed customized titanium alloy cage in the treatment of congenital cervical scoliosis

English Keywords:Congenital cervical scoliosis  3D printing  Titanium alloy cage  Concave side distraction

English Abstract:

  【Abstract】 Objectives: To explore the safety, feasibility, and short-term outcome of applying 3D printed customized titanium alloy cage into intervertebral space, in the surgical treatment of patients with congenital cervical scoliosis. Methods: Between July 2019 and January 2020, seven patients with congenital cervical scoliosis underwent distraction technique of concave side and treated with 3D printed customized titanium alloy cage. 4 were males and 3 were females. Age ranged between 6-15 years old (9.0±3.0 years old). The primary cervical spine deformity was Klippel-Feil syndrome in 5 cases. Of the other two cases, 1 was with malplasia of left lateral mass in the atlas, and the other was diagnosed with C4 right hemi-vertebra. The duration of surgery, estimated blood loss, perioperative neurological, vascular and wound related complications were recorded. Preoperative and postoperative appearance and radiology were observed and compared. Results: All patients′ surgeries were completed successfully. 6 patients received single site distraction and 1 patient received distraction in two sites. The duration of surgery ranged between 326-756min(502.4±149.8min), and the estimated blood loss ranged between 100-600ml(341.4±205.0ml). The height of 3D printed cage applied in the anterior column was 5-10mm(8.0±1.8mm), and the height of that applied between the facet joint was 7-12mm(9.5±1.9mm). No intraoperative complication occurred. 3 patients developed C5 nerve root dysfunction after surgery, with 2 patients on the concave side, and the other on the convex side. In 1 patient, revision surgery for screw adjustment was needed, and got fully recovered after revision surgery, and the other 2 patients recovered by conservative treatment. The follow-up period was 7-13 months(10.6±2.5 months). During the last follow-up, the cervical scoliosis in all patients was corrected significantly. Dynamic X-ray and CT scan showed intact binding between 3D printed cage and cortex. No translucent zone, subsidence, loosening, or migration of prosthesis was discovered. No pseudoarthrosis was discovered. The correction rate was 64.45%. Conclusions: The application of 3D printed customized titanium alloy cage in the treatment of congenital cervical scoliosis was with good feasibility and clinical safety. Short-term follow-up showed excellent results with a promising future.