Biomechanical Evaluation Of Different Fixation Methods In Schatzker Type Ⅵ Fractures Of Tibial Plateau

Objective:The purpose of this experiment is to compare the biomechanical properties of the most commonly used in clinical work such as raft technical locking plate, golf-type locking plate, golf-type ordinary plate and unilateral external fixation in the treatment of Schatzker type VI tibial plateau fracture, I hope the analysis can provide some useful information for clinical work.Method:1 Preparation of sample Choose the same area 40-50 age group 10 complete male cadavers of 40-50 age group from the same area, embalmed by 10% formalin, used in systemic anatomy class. All specimens had no history of tibial fractures, connective tissue disease, or hemiplegia. Remove 20 cases of corrosion adult cadavers’tibia bone,stripped clean soft tissue, leaving only the bone structure. All tibia specimens were observed by the naked eye, X-ray confirmed that no abnormalities, osteoporosis, and other anomalies.20 tibial bone specimens were undergone bone density examination, through statistical software (spss17.0) analysis P> 0.05, the difference was not statistically significant.20 tibial bone specimens were divided randomly into the raft locking plate technology (BLP Group), golf-type locking plate (GLP group), Golf-type common plate fixation (GCP group) and unilateral external fixator (UEF group), five specimens in each group.2 Preparation of the experimental model With oscillating saw cut on the proximal tibia to make fracture line based on the design of tibial plateau fracture Schatzker type VI model, and then fixed to the corresponding fracture fixation system model, as follows:Bamboo technical locking plate fixation group, outside using six holes 3.5mm locking plate fixation technique and matching screws; golf-type locking plate fixation group, with six holes to the outside of the golf-type 4.5mm locking compression plate fixation and matching screws; golf-general plate fixation group, outside 5 hole 4.5mm lateral plate fixation of proximal tibia,and matching screws; unilateral external fixator group, the outer use 1.1mm* 250mm connecting rod and matching skeletal traction fixed needle combination.3 Experiment method Artificial femoral condyle fracture models and specimens firmly fixed on the biomechanics, to maintain knee basic biology power lines. Each specimen is subjected to axial compression test experimental model, the axial compression load provided by the biomechanical machines, continuous rate of 1mm/min. Fixation fail criteria:①broken fixator ②screw fixation damage-loose bone contact surface ③screw emerge from bone fracture ④reduced fracture is cracked. Measurement data generated by the biomechanical device, and transmitted to the computer via TRAPEZIUM LITE X software to analyze and to record the corresponding tibial axial load displacement, axial stiffness, failure load.4 Statistical Analysis Applied SPSS 16.0 for four sets of data homogeneity of variance test (Levens), axial stiffness of each group, the failure loads and loads-sinking platform shift data were compared using a single method pairwise comparisons (ie LSD method) for multiple comparison. To test the significance of P<0.05, the difference was statistically significant.Results:BLP fixation set of axial stiffness, maximum failure load, compared with GLP fixation group (P=0.077, P=0.154) were not significantly different; BLP, GLP fixation group were compared with GCP, UEF fixation group (P<0.05), the difference was significant; GCP fixation group compared with the UEF fixation (P<0.05), and the difference was significant. UEF fixation set of axial stiffness, failure loads are the smallest. Under three type load strength, fixation displacement of BLP group were minimal, compared with GLP fixation group (P=0.496, P=0.242, P=0.063) which were not significantly different, BLP fixation group and GLP group compared to other two fixation the differences were statistically significant (P all<0.05); UEF fixed group sinking displacement is the largest within four groups.Conclusion:This study shows that under simulated physiological conditions, for tibial plateau fracture Schatzker type VI, bamboo technology plate and golf type plate anatomic axial stiffness and resistance to axial compression capabilities are similar, golf-type ordinary plate, followed by the external fixator group are poor.