Biomechanical comparison between resurfacing hip arthroplasty and normal proximal femur / 医用生物力学

ABSTRACT

Objective To investigate the variation of stress distributions on proximal femur after hip resurfacing arthroplasty (HRA) by using three-dimensional (3D) finite element method. Methods The 3D finite element model of proximal femur was reconstructed based on 64-slice spiral CT scan image data. Both the stress distributions on proximal femur after metal-on-metal HRA and normal proximal femur were studied, so as to analyze the biomechanical environment changes after HRA. Results After HRA, the superior, anterior, rear and inferior area of the proximal femoral head showed significant stress shielding, with peak stress of 0.60, 0.57, 0.66, 0.79 MPa, respectively, and stress shielding rate of 99.80%, 99.16%, 98.92%, 96.66%, respectively. Increased stress occurred in most regions of the distal femoral head, while stress shielding appeared only in rear area of the distal femoral head, with stress shielding rate of 4.92%. Increased stress occurred in anterior region of the proximal femoral neck, while stress shielding appeared in the superior, inferior and rear area of the proximal femoral neck, with shielding rate of 16.48%, 22.75% and 7.83%, respectively. Increased stress also occurred in inferior area of the distal femoral neck, while the remaining area showed stress shielding. The stress in greater trochanter increased by 9.22%, and the stress shielding rate for lesser trochanter area and basal area of femoral neck were 2.49% and 14.44%, respectively. Conclusions Stress distributions on most regions of proximal femur after HRA were similar to that on normal femur, and the stress transfer was close to physiological status, which could effectively avoid obvious stress shielding in proximal femur and preserve bone mass, which could contribute to normal physiological activity of patients.