ABSTRACT
BACKGROUND: During the hip replacement, selection of prosthesis often depends on patients' bone condition. There has been no gold standard for selection of prosthesis. It will be of scientific significance to select femoral prostheses implanted under different bone densities through three-dimensional finite element analysis and simulated contrast mechanical tests.OBJECTIVE: Three-dimensional finite element analysis was employed to select femoral prostheses according to different bone densities, and simultaneously simulated contrast mechanical tests were performed to determine the age criteria regarding the selection of femoral prosthesis during the hip replacement.DESIGN, TIME AND SETTING: An open experiment was performed at the Second Department of Orthopedics, First Clinical Hospital of Jilin University and Institute of Biomechanics, Jilin University between September 2006 and May 2007.MATERIALS: Freshly adult femoral specimens were harvested from cadavers.METHODS: Three-dimensional finite element models of femur were established using Solidworks software. Following the known formula, the bone density and elastic modulus at different age brackets were calculated and input into the computer. The human one-foot standing condition was simulated and pressure was loaded on the reconstructed femoral models.MAIN OUTCOME MEASURES: Some biomechanical characteristics of uncemented and cemented femoral prostheses, such as the distress distribution and initial micromovement at different bone densities, were measured.RESULTS: Relatively well-distributed whole distress and slight initial micromovement of uncemented femoral prostheses were found in male patients at 30-60 years old and in female patients at 40-55 years old. Symptoms of cemented femoral prostheses the same as the uncemented femoral prostheses were present in male patients at 60-70 years and in female patients older than 55 years old.CONCLUSION: Results of three-dimensional finite element analysis and simulated contrast mechanical tests suggest that uncemented femoral prostheses provide better therapeutic effects in male patients younger than 60 years and in female patients younger than 55 years than cemented femoral prosthesis.
ABSTRACT
In the present study, a three dimensional finite-element model of the human pelvic was reconstructed, and then, under different acetabular component position (the abduction angle ranges from 30 degrees to 70 degrees and the anteversion ranges from 5 degrees to 30degrees) the load distribution around the acetabular was evaluated by the computer biomechanical analysis program (Solidworks). Through the obtained load distribution results, the most even and reasonable range of the distribution was selected; therefore the safe range of the acetabular component implantation can be validated from the biomechanics aspect.