Finite Element Analysis On Treatmentdevelopment Acetabular Dysplasia By Acetabulum Covers

Objective: The objective is to investigate acetabulum covers and use the finite element to analyse, then to provide a new treatment method for the development of acetabular dysplasia.Method : 1. acetabulum covers is made out of titanium plate(net), including coverage, edge and locker. 2.Establishment of experimental model:the surgery is based on the approval of hospital medical ethics committee, as well as the understanding and agreement of the ill’s family. The ill, who is a 3 years old girl, is operated on the right side of acetabulum hypoplasia, with congenital dislocation of the hip line acetabulum stamp and femoral rotation osteotomy. According to the situation of the treatment of patients with hip joint laboratory specimen model is set up.(1)Patients with normal acetabulum model(normal mode): on the left side of the normal of the hip.(2)Acetabulum covers and acetabulum bone graft model(experimental model): line on the right side of acetabulum patients with hip joint with bone graft. 3. The finite element analysis: speciments of two models are CT scaned respectively, saved in Dicom format and imported with Minics software, thus a 3D finite element model is reconstructed. Simulation on one leg when the femoral head in weight-bearing area on the surface of the acetabulum surface load and the simulation calculation, record and compare separately the two basic information models’ stress value of drawing nephogram, stress value distribution on the acetabulum and displacement nephogram.Results: The acetabular cover has obtained the national patent. From thestress nephogram and acetabulum outer upper stress distribution curve, are concentrated in the upper part of the acetabulum outer stress two group model of loaddistribution, but not exactly the same, the normal model of stress concentration in the upper part of the acetabulum surface, the maximum value is 903E+07 Pascal, the experim-ental model of stress is mainly concentrated on the acetabular cover, m-aximum value 476E+09 group; two model of femoral head should be close to the value and stress distribution. The normaldisplacement model with pubic symphysis as a starting point to the direction of the scia-tic and iliac crest is increasing, the maximum displacement is 2.64 um, the ischial tuberosity, the minimum displacement is 2.10 um, the displace-ment of pubic symphysis; experimental model similar to the pubic symp-hysis as a starting point to the direction ofthe sciatic and iliac crest is increasing, the maximum displacement is 1.70 um, the ischial tubero-sity, the minimum displacement is 1.60 um, the pubic symphysis.Conclusions : 1 Acetabulum covers implant plus bone graft model and the normal stress distribution of acetabulum model. Acetabulum of lateral stress concentration is roughly similar. 2. Acetabulum covers implant plus bone graft model of acetabulum and SA share stress concentration, namely the acetabulum cover surface fixed point can reduce the acetabulum outer upper to stress concentration.