RESUMO
Objective To investigate whether a 3D printed model of the contrlateral healthy distal radius, especially its articular accuracy, helps anatomical reduction and precise reconstruction of the fractured distal radius. Methods The CT data of bilateral radii were collected from 15 normal volunteers ( 11 males and 4 females with an average age of 22. 8 years ) between November and December 2016. After 3D reconstruction of the bilateral distal 1/3 radii, solid 3D models of left radius were mirrored and generated by 3D printing. The data of right radii ( reference group ) were compared with the data of the solid 3D models of left radius acquired through a 3D scanner ( test group ) using deviation analysis. Results The maximum volume difference between the 3D printed model and the contralateral radius was 6. 86％. The average volume of the reference group was 19, 165. 82 ± 3, 250. 50 mm3 and that of the test group 19, 310. 65 ± 3, 305. 15 mm3, showing no statistically significant difference between the 2 groups ( t= -0. 941, P=0. 363 ) . The maximum surface area difference was 3. 84％ between the 2 groups. The average surface area of the reference group was 5, 075. 80 ± 549. 34 mm2 and that of the test group 5, 139. 43 ± 572. 48 mm2, showing a signifi-cant difference ( t= -2. 451, P=0. 028 ) . The 3D deviation analysis showed a mean positive deviation of 0. 37 ± 0. 10 mm and a mean negative deviation of 0. 30 ± 0. 07 mm. The maximum mean square root was 0. 65. The 3D deviation was distributed mainly within 1 mm interval, with a distribution frequency of 96. 27％. Conclusions A 3D printed model prepared by high precision equipment is accurate enough to guide reconstruction of distal radius fractures in adults. In the treatment of complex fractures of the distal radius, a 3D printed model of the contralateral healthy distal radius can be used as a reference to achieve anatomical reduction and precise reconstruction of the fractured distal radius.
RESUMO
<p><b>OBJECTIVE</b>To investigate the application of 3D printing and digital technology in preoperative assessment and planning of internal fixation surgery for complex tibial plateau fracture.</p><p><b>METHODS</b>Complex tibial plateau fractures and commonly used plates for tibial plateau were imaged using computed tomography (CT) to reconstruct the 3D fracture and plate models. The 3D models were used to perform virtual reduction and preoperative planning of internal fixation surgery with the most appropriate plates assisted by the 3D library of plates. According to the optimal plan, the 3D physical models of tibial plateau fractures and plates were 3D printed to simulate internal fixation operation. The effects of internal fixation were compared between the virtual surgery and the simulated surgery based on the 3D models.</p><p><b>RESULTS</b>The effects of internal fixation in the simulated surgery based on the 3D models were consistent with those of the virtual surgery. No significant difference was found in the screw length between the two surgeries.</p><p><b>CONCLUSION</b>The combination of 3D printing and digital design can improve the effects of internal fixation for complex tibial plateau fractures.</p>