Prosthesis Orientation Related FEA And Reverse Dynamic Analysis Of Hip Joint In THA

Objective:To explore the conrelation between morphology parameter and femoral neck fracture via make a measurement of femoral neck in X-ray and CT scan.To explore the biomechanical effect of hip prosthethsis using FEA.To explore the hip forece and muscle force via inverse dynamic analysis.Methods:(1)Retrospecitve study of medical image study invoving X-ray and CT scan were analysed during 2012 to 2016 to make an conrelation between morphology parameter and femoral neck fracture.(2)To explore the biomechanical effect of hip prosthethsis using FEA(3)The muscle simulation model of total hip arthroplasty was established to analyze the difference between hip joint force and torque during jogging and normal walking.Result:(1).The study included 180 patients with no obvious fracture and at the same time had X-ray and CT images of elderly people,including 110 males and 70 females,and the age range(60 ~ 82),with an average of 67.54 plus or minus 17.81 years.According to the anatomical parameters of X-ray and CT,the anatomical differences of the bilateral hip joint were not statistically significant(P > 0.05).According to CT imaging,the diameter of proximal tubular bone of femur fractures was increased and the cortical bone was significantly thinner,and there was a significant difference between normal and fracture patients.Using CT three-dimensional imaging is not all cortical bone defect was observed in all patients with femoral neck fracture phenomenon,including Garden type 1 patients,occurred in 81 patients with femoral neck fracture of cortical bone defect in 61 cases,accounting for 75.3% of the total patients.Bone defect is most common in the posterior femoral neck.(2)This study successfully constructed a three-dimensional finite element model of hip replacement.The model was constructed with a total of 442,559 model nodes,264,785 units of the model,and a clear articulation of the hip joint.When the acetabulum and the outer Angle of the acetabulum were outside the normal range,there were visible high stress areas in the acetabular bone,the acetabular prosthesis,the lining and the prosthesis of the femur.The stress concentration area is mainly distributed in the lower part of the acetabulum,above the acetabulum,and above the lining.The region of the femoral neck of the femoral hilum has obviously high stress concentration.If the acetabular region is in high stress concentration area for a long time,it can easily cause the bone absorption in the acetabular region,resulting in the dislocation of the acetabulum and the failure of the prosthesis,which seriously affects the quality of life of the patients.When the anterior dip Angle and the outer Angle of the acetabulum are in normal range,the relative high stress area can be seen in the acetabular bone,the acetabular prosthesis,the lining and the prosthesis of the femur.There was no obvious high stress concentration area in the hip area of acetabulum,above the acetabulum,and above the lining.There is a relatively high stress concentration area in the lower part of the femoral neck of the femoral prosthesis,but the stress concentration in the anterior Angle of the acetabulum and the outer corner of the femoral head is significantly lower than that of the normal range.(3)Under normal walking and jogging,total hip arthroplasty was significantly different between the joint forces and the torque.Conclusion:(1)Normal human bone structure has symmetrical distribution,fracture and other diseases can be used to predict the side data using the anatomical parameters of the hip joint.In this way,we can have a sufficient theoretical basis to compare the anatomical differences between healthy and fracture patients.To sum up,anatomy parameter can affect the incidence of fracture,the femoral head and femoral neck diameter,neck stem Angle and eccentricity was significantly related with femoral neck fracture parameters,such as,in terms of fracture prediction and assessment is of great significance.(2)The differences in the position of the acetabulum and the outside Angle of the acetabulum have a decisive effect on the biomechanical distribution of the acetabulum.With the decrease and increase of the outer Angle and the former inclination,the local stress concentration of the acetabular prosthesis is obvious.The greater the Angle of the outspread Angle and the front tilt Angle,the higher the stress and strain peak.The acetabular prosthesis is susceptible to loosening in high stress and high strain state,which can lead to the failure of acetabular prosthesis.(3)Anybody can use human modeling and simulation system,accurate analysis of various actions or conditions around the hip muscle activation degree and the stress distribution,the innovation and development of musculoskeletal biomechanics plays an important role.