Biomechanical Study Of Transverse Acetabular Fracture Treated With Internal Fixation Methods

Acetabular fractures are mostly caused by high-energy impact injuries unstable pelvic fracture, open reduction and internal fixation generally take the treatment. Fixation devices that use a fixed three-dimensional anatomy of the fracture sites were reset, so that faster growth of the healing fracture site. In recent years, scholars of the acetabular fracture had been more in-depth research carried out. Biomechanical acetabulum pelvis is widely used by many scholars to study issues related to the mechanical properties of the pelvis.Fixture plays an important role in the experiment, but few articles on the design of the pelvic clamp experiments done in detail. Wether it can strictly guarantee the pelvis standing posture, no damage to the pelvic structure and to the bone and can ensure the normal mechanical pathways pelvis without increasing the excess load has a fatal influence to the results of the exeperiment.Due to the damands of the doctors and other conclusions on this field, this article has found out the current fixture problems and set up experimental platform against the problems above. Based on various physiological parameters of the pelvis, designed the pelvis special fixtures and the mechanical properties muscle simulator. This device is suitable for various sizes of specimens, can strictly guarantee the pelvis standing posture, no damage to the pelvic structure and to the bone and can ensure the normal mechanical pathways pelvis without increasing the excess load. Muscle simulator simulation to achieve the mechanical properties of muscles, by increasing the device make the experimental conditions more closer to the true physiological state of the pelvis.Using the jig we designed, we did biomechanical experiments according to the requirements of the doctors and patients extent of exposed injury and make three different groups in different fixation modes. The mechanical properties and stability were compared. The three groups were: posterior column long plate and posterior column short plate; posterior column plate and posterior column long plate and anterior column lag screw; double-column screw and double columns plate. Meanwhile, compare the three kinds of two-column fixed methods.The Conclusions are as follow: First, by the verification experiment confirmed that the fixture does not impact the mechanical transmission on the pelvis. Pelvic jig can fully meet the test requirements; strictly ensure the experimental profile, suitable for any sample with different size, no effect on the direction of the mechanical transmission. There is no damage to the bone and structure of the pelvis, remedy the current problems of common fixture. No crack or dislocation occurred during the experiments. In the biomechanical experiments the internal fixation devices never displaced. Increased muscle simulator results closer to the truth. Second, we draw the following conclusion through the experimental data: posterior column long plate is better than posterior column short plate which the short plate with a unstable fracture line displacement over 3mm; posterior column long plate and anterior column lag screw is better than the posterior column plate alone; double-column screw is better than double columns plate. But no significant difference were founded among the double column fixation methods; anterior column screw plate fixation was superior to the posterior column of the posterior column plate.