Application Of 3D Printing Technique In The Treatment Of Old Pelvic Acetabular Fracture

Objective:1.To explore the diagnosis and treatment of old pelvic acetabular fracture;2.Analysis of the application value of 3D printing technique in individualized diagnosis and treatment of old pelvic acetabular fractures.Methods:The data of 35 patients with old pelvic acetabular fracture who were treated surgically from January 2011 to January 2018 in the Department of Trauma Orthopaedics of Shandong Provincial Hospital were analyzed retrospectively.According to the preoperative planning and intraoperative guidance with or without 3D printing technology,the patients were divided into two groups:the 3D group(preoperative planning and intraoperative guidance with 3D printing technology)and the conventional group(evaluation with conventional imaging data).The 3D group included 17 patients,11 males and 6 females;the age ranged from 18 to 45 years,with an average age of 32.2 years;and the time from surgery to the first injury ranged from 1.5 to 6.0 months,with an average age of 3.6 months.The routine group also included 18 patients,12 males and 6 females;the age ranged from 23-43 years,with an average age of 31.6 years;and the time from surgery to initial injury was 1.0-5.0 months,with an average of 3.7 months.In the 3D group and the conventional group,the initial pelvic fracture was classified according to Tile classification.The 3D group included 11 cases of C1 type,4 cases of C2 type,2 cases of C3 type,and 7 cases were combined with acetabular fracture.The conventional group:2 cases of Tile type B3.There were 9 cases of C1 type,5 cases of C2 type,2 case of C3 type,and 5 cases were combined with acetabular fracture.In the 3D group,the DICOM data were obtained by CT scan before operation,and then the 1:1 pelvic model was printed by Mimics software.The preoperative planning included fracture reduction,osteotomy design,plate pre-bending,plastic fixation and so on.In the routine group,the X-ray and CT images were observed before operation,and the reduction and plate shaping and fixation were performed according to the experience during the operation.The intraoperative bleeding volume,operation time,fluoroscopy times,visual analogue pain score(VAS),Majeed function score and postoperative complications were observed and compared between the two groups.Results:There was no significant difference in the preoperative general data between the 3D group and the conventional group(P>0.05),which was comparable.The average amount of bleeding during operation in 3D group and conventional group was(2400.0+466.4),(2882.3+821.8)ml,and the average operation time was(213.5+30.0),(260.6+66.0)min.The average times of fluoroscopy during operation were(10.4+3.4),(13.1+4.1).There were significant differences between the two groups(P<0.05).The average follow-up time was 12.0,11.4 months in 3D group and conventional group respectively.The average VAS scores of 3D group and conventional group were(1.7+1.3),(2.8+1.8)respectively,with significant difference(P<0.05);the average Majeed scores of post-operation were(82.9+3.9),(81.6+4.1),with no significant difference(P>0.05).Conclusion:Proper open reduction and internal fixation for old pelvic fractures can obviously improve the symptoms and obtain satisfactory surgical results.The application of 3D printing technique to individualized surgical planning before operation is helpful to preoperative diagnosis and evaluation of fractures,design osteotomy,preview simulated operation for reduction and fixation,and effectively shorten the operation ti:me compared with the traditional operation.The amount of intraoperative bleeding and complications were reduced,and the quality of reduction and clinical effect were improved.