The use of CT scan and stereo lithography apparatus technologies in a canine individualized rib prosthesis

ObjectiveTo design and fabricate canine rib prosthesis with full geometric shape using computed tomography (CT) scan combined with computer-aided design (CAD) and stereo lithographic (SLA) technologies and to evaluate the accuracy of this method.MethodsAfter scanned on 64 rows helical CT, the cortex part of the right 7th rib was selected as the prototype for design and manufacture of the rib prosthesis and image data were stored as DICOM format. Three-dimensional (3D) surface reconstruction was applied to produce 3D image of the 7th rib and results were outputted as STL format which were then modified by UG software for establishment of CAD model.ResultsThe rib prosthesis with full geometric shape was obtained based on CT scanning and SLA technique. About 30,000 point cloud data were acquired after 3D laser scan of the ribs. When comparing the rib prosthesis with the rib prototype, the maximum positive deviation, maximum negative deviation, average deviation and standard deviation were 1.764 mm, −2.126 mm, 0.183/−0.253 mm and 0.346 mm, respectively. There were about 88.17% of the point cloud data within the range of ±0.5 mm.ConclusionIt is feasible to design and fabricate rib prosthesis with full geometric shape by using CT scanning technology combined with CAD and SLA technologies. This method is fast, convenient and precise for manufacturing prosthesis. Optimization and improvement could be processed based on the deviation suggested by the scanning.