Finite Element Analysis And Case Report Of The Intertrochanteric Fracture With Posterior Coronal Splited

Objective1. Build fracture models of intertrochanteric fracture with posterior coronal splited and make internal fixation with simple DHS or DHS+ lag screw. Using finite element method to compare the mechanic differences in different internal fixation. It could provide the correct method in selection based on theroy for such fracture.2. Through cases report, analyze the therapy differences of the intertrochanteric fracture with posterior coronal splited by simple DHS or DHS + lag screw ( stainless steel wire or ethibond suture ). It could provide the correct method in selection based on practice for such fracture.MethodsFirstly, choose a volunteer to make spiral CT scan on the femur and achieve data for buiding 3-D finite element models. Using Minics12.11 and Abaqus6.9, the numerical models for fracture have been built. By importing DHS and lag screw geometry parameters, setting boundary and loading conditions, get the stress distribution, stress and displacement values, then do some biomechanical analysis. Secondly, by case review, divide all the cases into two groups: fixed group and unfixed group according to fixing posterior coronal splited fracture or not. Compare the differences between the two groups, operation time, peri-operative bleeding and the function recovery of joints,then do some statistical analysis.Results1. By the finite element analysis, find that the stress distribution , stress and displacement of the femur fracture and internal fixation are not the same in the three kind of fracture fixation models. It shows that in the DHS form of internal fixation stability: pure type Evansâ…¡fracture with DHS internal fixation > type Evans II fracture + 1/4 posterior coronal position splited with DHS+ lag screw internal fixation > type Evans II fracture + 1/4 posterior coronal position splited with simple DHS internal fixation.2. Through cases analysis, the two groups in operation time and peri-operative bleeding have no significant differences, but in the postoperative joint function recovery has significant differences.Conclusions1. The intertrochanteric fracture with posterior 1/4 coronal splited by DHS + lag screw internal fixation , the lag screw can strengthen the role of the DHS fixation the intertrochanteric fracture.2 The intertrochanteric fracture with posterior coronal splited , when internal fixation the coronal splitted fracture, it could help the hip joint function recovery . .