Finite element method for analyzing the stress distribution of acetabulum under different loads / 中国组织工程研究

ABSTRACT

BACKGROUND:The hip is a complicated structure and irregular in shape. It is hard to measure stress distribution and transmission. OBJECTIVE:To establish a three-dimensional finite element model of the hip joint and upper femur, and analyze the stress distribution and transmission characteristics of the acetabulum region under different loads, and explore mechanics mechanism of hip fracture based on CT data. METHODS:The three-dimensional finite element hip and femur model were reconstructed in Mimics 14.0 based on the CT data of a healthy adult man. After dividing mesh, assigning material and transforming into finite element model, the stress distributions of anterior wal , the top, and the posterior wal of the acetabulum, the stress of acetabulum areas and displacement of acetabular unit were calculated with finite element software Ansys 13.0 software under 300, 600, 900 and 1 200 N. RESULTS AND CONCLUSION:(1) A three-dimensional finite element model of the hip and the femur was successful y established, consisting of 284 183 nodes and 160 665 units. (2) The characteristics of the stress distribution of acetabulum regionthe maximal stress was concentrated on the posterosuperior part of acetabular crest, fol owed by the posterior wal and the anterior wal in order in upright position under different loads. The stress transmitted by four waysfrom acetabular crest to ilium, along linea terminalis of pelvis to sacroiliac joint, in the acetabular sockets, and along the pubic ramus. The stress and the propagation distance were increasing as the loads increased. Acetabular element stress variable was increased. (3) Above results indicated that three-dimensional finite element model of the human hip joint established by Mimics 14.0 based on CT data matches the anatomical structure in a great degree, could be used in the biomechanics analysis under different loads, and has a guiding significance for design of artificial hip prosthesis.