Design of an anatomic plate of ulna coronoid process by 3D printing and computer software / 中华创伤骨科杂志

ABSTRACT

Objective:To design an anatomical plate of ulna coronoid process using 3D printing and computer model design software based on a collection of CT scanning data of the ulna coronoid process.Methods:The CT scans of the elbow joint with no obvious anatomic variation, no fracture, or no history of elbow operation were collected which had been taken at Trauma Center, The First Affiliated Hospital of Kunming Medical University from September 2017 to January 2022. There were 52 males and 50 females. RadiAnt DICOM Viewer and Mimics Medical 21.0 were used to visualize the CT data of the elbow joint of 102 volunteers. The software was used to measure the angle between the tip of the ulna coronoid process and the tuberosity of the ulna, the width at 1/2 height of the ulna coronoid process, the distance between the tip of the ulna coronoid process and the horizontal plane of the ulna tuberosity, and the safety angle for screw placement. After the values were measured, Siemens Ungraphics NX12.0 software was used to design the anatomical plate and the screw guide device of the ulna coronoid process. After the plate model was designed, a 11 actual plate model of the ulna coronoid process was produced by 3D printing. The actual plate model was placed onto an adult model of the ulna coronoid process and an adult cadaveric specimen of the ulna coronoid process to verify its matching degree. An in vitro operation was simulated using the plate model to verify its operability. Results:There were no significant differences between the left and right sides in the angle between the tip of the ulna coronoid process and the tuberosity of the ulna, the width at 1/2 height of the ulna coronoid process, the distance between the tip of the ulna coronoid process and the horizontal plane of the ulna tuberosity, or the safety angle for screw placement in either males or females ( P>0.05). There were no significant differences between males and females in the angle between the tip of the ulna coronoid process and the tuberosity of the ulna or in the safety angle for screw placement ( P>0.05). There were statistically significant differences between males and females in the width of 1/2 height of the ulna coronoid process and the distance between the tip of the ulna coronoid process and the horizontal plane of the ulna tuberosity ( P<0.05). However, the experiments on computer simulative adaptation and plate model simulative adaptation found that the anatomical plates of the ulna coronoid process designed on various parameters of males and females were exchangeable, leading to similarly good marching degrees and safe angles for screw placement. Conclusions:The anatomical plate of the ulna coronoid process designed in this study demonstrates a good fit and a safe angle for screw placement, basically achieving the goal expected to provide a basis for fabrication of a titanium alloy plate. In design of an anatomical plate of ulna coronoid process, it is not necessary to differentiate males from females or to differentiate the left side from the right one, because only a general plate can be used for both males and females and for both the left and the right sides.