[Von Mises stresses research of three-fin acetabular components and pelvis bone with segmental bone defect of acetabulum using rosette strain gages method].
OBJECTIVE
To set up the experimemtal model with superior segmental bone defect in acetabulum and implant the three-fin acetabular component, and examine the Von Mises stresses of pelvis bone with simulating single leg position in vitro using rosette strain gages method (RSGD).


METHODS
Four kinds of three-fin components were made based on measurement of diameter, depth and roof thickness of acetabular specimens. These kinds of three-fin acetabular components based on spreaded degrees of lateral fins (0, 36.45 and 60 degrees). The superior segmental bone defect of acetabulum in 4 cadaver pelvis specimens was made,then simulated the actual position to place implant into acetabular bone. A blank control group was set up. After being fit up the 7 sets of rosette strain gages,then specimen to test the pelvic Von Mises stresses simulating the static load of single leg on the mechanic machine. Progressive load was graded into 150, 300, 450, 600, 750 and 900 N. We obtained the strains informations about loaded and un-loaded pelvis bone.


RESULTS
Based on computed the strains informations,we were informed the Von Mises stresses about pelvis bone. The maximal Von Mises stresses of selected local position was 6.93 MPa and the minimal Von Mises stresses of selected local position was 1.08 MPa.


CONCLUSIONS
Providing the data about the main part of three-fin acetabular component to optimize spreaded degrees of lateral fins.
Liu
Yuzeng
Y
Department of Orthopaedics, the 306th Hospital of PLA, Beijing, 100101, PR China. liuyuzeng306@sohu.com
Wang
Jifang
J
Zou
Dewei
D
D000077:Acetabulum / Q000293:injuries*; D019644:Arthroplasty, Replacement, Hip; D002102:Cadaver; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D010384:Pelvic Bones / Q000502:physiology*; D013314:Stress, Mechanical; D016474:Weight-Bearing