[Biomechanical study on femoroplasty-augmentation for prevention of osteoporotic hip fractures].

Objective: To explore whether femoral plasty can improve the fracture resistance of osteoporotic femoral specimens and prevent hip fracture, and to compare the difference of mechanical strength changes between two different femoral plasty methods in osteoporotic femoral specimens, so as to determine the best strengthening area of the plasty.

Methods: Eighteen pairs of fresh osteoporotic femur specimens were collected and divided into two groups, A and B, 9 pairs in each group. Nine fresh osteoporotic femur specimens in each group were randomly selected for enhancement, and the corresponding contralateral specimens were used as control group. In group A1, the enhancement areas were femoral head, femoral neck, femoral trochanter and subtrochantericregion. And in group B1, the enhancement areas were femoral head, femoral neck and femoral trochanter region. The amount of cement injected into the femoral neck was recorded and the surface temperature of the femoral neck was measured. All specimens were biomechanically tested under simulated falls. Load-displacement curves, final loads were recorded. The final energy and stiffness of specimens were calculated. The biomechanical differences between the specimens of the enhancement group and those of the corresponding control group were compared, and the mechanical changes of the specimens by two different enhancement methods were compared.

Results: Compared with the control group, the ultimate load and energy of the specimens in the enhanced group increased significantly, but the stiffness did not change significantly. There was no significant difference in final load and energy between specimens strengthened by two different methods.

Conclusion: Femoral plasty has the advantages of minimally invasive, simple operationand remarkable effect. It can be used as a new method to prevent osteoporotic hip fracture.