Design And Biomechanical Study Avulsion Fracture Fixation Ligaments Stop

PurposeThe primary purpose of this research is to design a new type of fixture equipment for the treatment of tendon avulsion fractures or bone and tendon/ligament and adherent section injury, and to build an animal model for medial collateral ligament avulsion fracture or bone and tendon/ligament and adherent section injury, also the author wants to contrast fixation strength with different methods of internal fixation according to the experimental results. Clinical follow up plan is to observe the long term treatment effects of this new type of fixation method in treating medial collateral ligament avulsion fracture.MethodThe author anatomized5fresh human knee joint specimens and5fresh pig knee joint specimens, and then contrasted the anatomical feature of the medial collateral ligament. The20pigs were opted in18-24months old, weighing125-150Kg. The author built three degree injury model of pig knee joint medial collateral ligament, randomly divided them into4groups and put them into the fridge. The fracture fragments were separately fixed with GⅡ(JNJ non-absorbable bone-anchor),2.0kirschner wire with GⅡ, AO4.5*3.5hollow rivets with GⅡ. and self-designed new type of fixation equipment. The pig femurs were put in the loading disc of Shimadzu AG—1soKN material tensile testing machine, and the tibias were put in the fixtures. The author conducted the internal lateral stress experiment with the knee joints simulated in extending position. Maximum tensile resistance strength and displacement quantity were recorded by the high performance data acquisition machine. The experimental results are based on the data processed with spss15.0software system.ResultsWith the similarity of human and pig knee joint anatomical structure, it’s feasible to conduct alternative mechanical experiment. The medial collateral ligament of an adult human is (22.8±3.3) mm long, the check point of femur is (4.53±0.7) mm wide, the check point of tibia is (6.71±0.8) mm wide.ConclusionThe new type of fixation equipment is more solid than traditional fixation methods in fixing fracture fragments, through the biomechanical experiment. It’s more simple, economical and minimally invasive, with less postoperative complications. The patients would save more money in the surgery. Also, this new type of fixation equipment can fix avulsion fractures and bone and tendon/ligament and adherent section. Knee joint function would recover better. With GⅡ, the effects of fixation is not quite sufficient. Theoretically, this new type of new fixation equipment is equal to the fixation strength of hollow rivets+GⅡ. In the same time, this new method is more simple, minimally invasive and economical.