Application Of Computer-assisted Model Design Combined With 3D Printing Technology In The Treatment Of Spinal Complex Diseases

Objectives:To explore the specific methods and validation of computer-assisted design models combined with 3D printing technology in the treatment of complex diseases of spinal surgery,especially spinal deformity and spinal tumors.Methods:31 patients with complex spinal diseases who were treated in orthopedics in the Second Affiliated Hospital of the Army Military Medical University from January 2016 to June 2018,including 26 patients with spinal deformity and 5 patients with spinal tumors,were selected.The preoperative imaging DICOM raw data was collected,the Mimics software was used to reconstruct the operation area model on the computer,the operation process was simulated and reconstructed the postoperative effect.Finally,the actual model was created by using 3D printing technology to guide the treatment.To analyze the difference between these patients’ preoperative morphology,immediate operation result,the final follow-up result and the design model.Based on the different radiological enhanced manifestations,the shape of tumor was defined when in the process of computer model designed,and different colors were distinguished from normal tissues and tumors when printing 3D models.Study the similarity between the reconstruction model and the actual situation.Results:All 26 patients with spinal deformity had a successfully operation,the follow-up period was 3 to 24 months,and the average follow-up period was 9.5 months.The statistical results showed that the mean values of preoperative spinal coronal,sagittal Cobb angle,AVT and SVA were 61.7±18.1°,48.3±29.3°,68.5±22.5 mm,37.7±25.8 mm,the postoperative values were 23.3±9.1°,22.0±12.3°,36.1±17.3 mm,and 17.1±13.0 mm,respectively,and the difference was statistically significant(P<0.05).The mean values of the design models were 22.1±7.7°,21.4±10.8°,34.7±14.5 mm,and 17.6±12.4 mm.The mean values of the last follow-up measurements were 23.5±8.8°,22.1±11.9°,36.2±16.8 mm,and 17.4±12.5,respectively,the difference was not statistically significant(P>0.05).Five patients with spinal metastases successfully constructed a 3D printed model and successfully performed the operation.The average operation time was 264 minutes,the average blood loss was 1680 ml,the follow-up time was 3 to 13 months,and the average hospitalization day was 15.4 days,the overall condition of the patient recovered well after the operation.Conclusions:Preoperative computer three-dimensional reconstruction,and reasonable design of postoperative results,combined with 3D printing technology to create a model,can provide better surgical guidance for spine surgeons.In this study,the postoperative deformity of patients was significantly improved compared with preoperative changes.The consistency between the postoperative follow-up data and the preoperative design model data is good,indicating the effectiveness of surgical treatment and the simulation reliability of the 3D printed model.The tumor model designed according to the data of spinal tumor patients’ can accurately reflect the adjacent relationship between tumor and normal tissues,and these models provided a reliable and intuitive information to surgeons who could make better operations.Therefore,the combination of computer-assisted design and 3D printing technology has real value and practical application in spinal surgery.The 3D printing technology deserved further research and widely promotion in spinal diseases.