They do not specialise in any specific industry but provide public access to 3D printing. They provide a fast service (less than 10-day turnaround) and charge based on volume in cm3 and the material used to produce the model. We used a plastic-like material PA 2200, which is printed selleck using the technique of Selective-Laser-Sintering (SLS). SLS uses a high power laser (e.g., a carbon dioxide laser) to fuse small particles of plastic or metal, ceramic, or glass powders into the designated object. PA 2200 is a white nylon, which is strong and flexible. It is also one of their most detailed (minimum detail 0.2mm) materials. Minimum wall thickness of structures printed can be 0.7mm and maximum size of printed structure can be 31 �� 23 �� 18cm (http://www.shapeways.com/materials/white_strong_flexible��accessed 19/09/11).
It is stable up to a temperature of 80��C.4.6. Assessment of the ModelThe models produced were then validated against the 3D CT scan images using digital electronic vernier calipers to take multiple measurements at defined intervals (20mm) along the model bones and at the same points on the CT scan (Figure 8). Two observers measured the same segments independently on three separate occasions.Figure 8Measurements on CT scan.The measurements were analysed for a statistically significant difference with a paired Student’s t-test. The P values showed no statistical difference in dimensions between the printed models and the original CT scans (see Tables Tables11 and and22).Table 1Table 24.7. Model ProductionWe produced a 3D reproduction of malunited forearm bones from standard CT DICOM data using free open-source software.
The models cost a total of ��77 including shipping to the department for both the radius and ulna (Figures (Figures99 and and10)10) and took only 7 days to arrive.Figure 9��Model�� radius and ulna.Figure 10Distal radius showing level of physeal detail.5. DiscussionThe main objective was to establish a simple and cost-effective method to produce accurate and detailed physical 3 dimensional models from standard CT scans. We aimed to do this quickly without specialist expertise. With the use of OsiriX and Meshlab on a standard personal computer and a publicly accessed commercial online 3D printing service, an inexpensive (��77 compared with ��500�C��900) model suitable for preoperative planning can be produced in a short time frame (7 days).
The data from the measurements confirmed the fidelity of the model produced. Other reports have used the technique of Carfilzomib SLS [18]. However, none are known to have used Osirix [22] to manipulate the data for this purpose.The measurements and validation of 3D models can undoubtedly be improved and are the subject of further work. This study focused on simple-shaped long bones with thick periosteum allowing for noncomplex image processing.