Analysis of the 3D prototyping in the surgical correction of congenital kyphoscoliosis

Abstract

Objective. To analyze the advantages of additive technologies and 3D modeling in surgery for severe congenital spinal deformities caused by mixed and non-classified developmental anomalies, including assessing the quality of transpedicular screws. Material and Methods. A total of 20 patients with complex spinal anatomy caused by congenital vertebral anomalies were treated. Nine patients had complex unclassifiable anomalies of the spine, 11 had mixed anomalies, 3 of them had aplasia of the structures of the spinal column. In order to assess the results, patients were divided into two groups of 10 people. In Group I, standard preoperative preparation was performed according to X-ray, CT and MRI data. In Group II, preoperative preparation was accompanied by the use of a prefabricated 3D model of the patient’s spine. CT data were used to create STL-models which were printed using 3D printer. To analyze the effectiveness of 3D prototyping in preoperative planning, a survey among surgeons specializing in pathology of the spine was conducted. Results. Survey results demonstrated that there were cases of changes in surgical treatment tactics after the 2nd stage of the survey, based on the results of applying standard methods of radiation diagnostics and 3D model of the entire spine with prototyping of the thoracic, lumbar, and sacral spine. In 25.3 % of cases, tactics were changed. Significant improvement in surgical treatment results were observed in Group II with preoperative 3D modeling (94.9 % without screw malposition), compared to Group I in which surgical correction was performed using standard methods of imaging (78.1 % without screw malposition). Conclusion. 3D modeling allows increasing the accuracy of the placement of transpedicular screws and reducing the risk of malposition, which favorably affects the biomechanical properties of the instrumentation and reduces the risk of damage to neural structures. The use of 3D modeling can statistically significantly reduce the time taken to install one screw, and the number of x-rays required. Reducing the number of images allows you to reduce radiation exposure not only to the patient, but also to the staff of the department.

Keywords

• congenital anomalies
• 3d modeling
• transpedicular fixation
• scoliosis