Application of full-scale three-dimensional models in patients with severe spine deformities

Abstract

Introduction. Correction of severe spinal deformities remains challenging. Our objective was to describe our experience using three-dimensional (3D) models and individual implants for the correction of severe spinal deformities. Methods. Full-scale 3D models were custom-made for 20 patients with different types of spinal deformities: 5 patients with severe spondylolisthesis, 3 patients with upper cervical deformities, 2 patient with neurofibromatosis, 2 patients with paralytic scoliosis, 7 patients with severe congenital deformities of spine, one patient with tumor of sternum. 3D models were manufactured using rapid prototyping from CT data. In all cases 3D models were used for planning surgical interventions. Using models as a template, individual implants were created for the fixation of the spine in 11 patients. In 2 patients with C1-C2 deformity, anterior transoral C1-C2 fixation using individual plates was performed. In one 9 yrs patient with neurofibromatosis, secondary deformity and sacral hypoplasia, and in 4 patients with paralytic and congenital scoliosis instrumental deformity correction was performed combined with lumbo-pelvic fixation using individual iliac plates. In 4 patients with spondylolisthesis, additional anterior L5-S1 fixation using individual plates and long threaded cages was performed, in one patient with tumor of sternum a custom-made sternum substitute implant was manufactured. Results. The follow-up period was 2 years, with neurological restoration and stable fixation in all cases. Conclusion. Full-scale 3D models offer a useful tool in preoperative planning, allowing full-scale stereoscopic recognition from any direction and distance with tactile feedback. Full-scale 3D models can be effectively used for creating individual implants.