Biomechanical Study And Investigation Of The Value Of Clinical Application On The Anatomical Plastic Splint For Proximal Humerus

ObjectiveAn anatomical plastic splint for proximal humerus was designed and developed on the basis of the anatomical structure and fracture type of proximal humeral, together with the treating principle of “combining dynamic and static methods and emphasizing on both sinews and bones”. The study aims at the biomechanical research on the new type of splint, providing a scientific theoretical basis for its further optimization and improvement, making the anatomical plastic splint for proximal humerus more adaptable for human shoulders and more convenient to be fixed and adjusted, exploring its value and effectiveness in clinical application value, hence determining its innovativeness.Method1.Developing a new type of splintAccording to the anatomical structure and fracture type of proximal humeral, on the basis of plaster models, the anatomical plastic splint for proximal humerus was made out from proper materials.2.Biomechanical experiment2.1According to the mechanical characteristics of the material, the fixing belt of anatomical plastic splint for proximal humerus and traditional splint belt were investigated by means of tensile experiments to compare which one was more suitable for stabilizing the splint.2.2By testing the damping condition of fixing belt’s binding force in anatomical plastic splint for proximal humerus in normal functional exercises, whether the new type of splint can provide persistent and effective binding force or not was determined.2.3The volunteers’ degrees of blood oxygen saturation of their fingers before and 12 hours, 24 hours, 36 hours and 48 hours after they wore the anatomical plastic splint for proximal humerus were measured. And by observing the splint’s local compressing on the fixed limb and its influence on far-end blood supply, the safety, reliability and comfort of the splint were confirmed.3.After studying the anatomical plastic splint for proximal humerus with biomechanical method, according to the characteristics that proximal humerus fracture often happens on the elders and micromotion’s function of promoting facture healing, the application value of the new type splint was further explored.ResultsAccording to the design, the anatomical plastic splint for proximal humerus was made out successfully, and was granted the national utility model patent. Biomechanical test results are as follows:1.In the case of tension less than 100N(10.20Kg), the new splint fixing belt has a higher Young’s modulus than the traditional band.2.The fixing band of large, medium and small groups of new splint at different locations,at 8 time points after fixation, the measured binding force are at the range of 700~900g which had been set beforehand, and the fixing band of each group did not loose obviously.3.The oxygen saturations measured before wearing the large, medium and small groups of the splint, and 12 hours, 24 hours, 36 hours and 48 hours after wearing were in the normal range.Conclusion1.New type fixing band of splint has stronger resistance deformation ability with tension than traditional splint ligation, and is more suitable for the fixation of the anatomical plastic splint for proximal humerus.2.In accordance with the mechanical properties of the shoulder and proximal humerus of human body, the anatomical plastic splint for proximal humerus can permanently and effectively maintainws the stability of fracture fixation, and its comfort in wearing,easiness to operate, safety and reliability has met the original design requirements and targets.3.It is accurate and effective to study the binding force of new type of splint with digital image correlating method. And the method is valuable to be popularized in the determination of biomechanical experiments.