Development and Biomechanical Testing of a Custom-Made Plate for Sternoclavicular Joint

Sun Yuanlin; Yang Yunkang

Abstract：Objective To develop a specialized anatomical locking plate for sternoclavicular joint fracture-dislocation and verify its advantages in treating this condition.Methods(1)Design and fabrication of a dedicated sternoclavicular joint plate,consisting of three components:A manubrial plate,a clavicular plate,and a sternoclavicular joint plate.The manubrial plate is hook-shaped to fit the anterior and posterior surfaces of the sternal manubrium and the sternal notch;the clavicular plate is flat,designed for intimate contact with the superior and anterior surfaces of the proximal clavicle;and the sternoclavicular joint plate connects the manubrial and ipsilateral clavicular plates.The length of the clavicular plate can be extended according to clinical needs,and the plate is manufactured from titanium alloy.(2)Twenty sternoclavicular joints from 10 cadaveric specimens were prepared as complete dislocation models and randomly divided into two groups(n=10 each):the experimental group was fixed with the dedicated sternoclavicular joint plate,while the control group was fixed with a distal radius oblique T-shaped locking plate.After embedding and fixation,both groups were subjected to mechanical testing using a universal testing machine to simulate injury mechanisms,including compression,torsion,and pull-out tests.Results Under loads of 0～25 N,the angular deformation increased linearly with loading in both groups,with the experimental group demonstrating superior resistance to compressive deformation compared to the control group(P＜0.05).At a torsion angle of 0 °～10 °,the torque of the specimens in both groups increased linearly with the increase of torsion angle,and the torsional deformation resistance of the experimental group was stronger(P＜0.05).There was a statistically significant difference in the maximum pull-out force between the experimental group and the control group(P＜0.0 5),and the experimental group had higher fixation strength.Conclusion The custom-made sternoclavicular joint plate developed in this study features a structural design highly consistent with the biomechanical characteristics of the sternoclavicular joint,providing stable mechanical support with straightforward surgical application.Future clinical studies will be conducted to further validate its therapeutic efficacy.