Biomechanics analysis for the treatment of ischemic necrosis of the femoral head by using an interior supporting system.

OBJECTIVE: This work aims to perform a biomechanical test to evaluate the effect of interior supporting system and tantalum rod in simulating the treatment of ischemic necrosis of the femoral head.

METHOD: Three models were established: control group (group A), interior supporting system group (group B), and tantalum rod group (group C). Step-by-step loading was applied on the top of the femoral head until femoral head damage occurs by using the testing machine of the material test system. Strain and maximum load were applied until the femoral head collapses. The damage to the trochanteric fossa, femur calcar, and greater trochanter were compared.

RESULTS: (1) The strain on the trochanteric fossa shows the following order: group C > group A and group B (P < 0.05). No significant difference was observed among groups for the other parts (P > 0.05). (2) The maximum load in group B is larger than that in groups A and C (P < 0.05). No significant difference in the maximum load was observed among the three groups when the femoral head was destroyed.

CONCLUSIONS: The compression strain and bearing load of the femoral head are close to normal after placement of an interior supporting system and tantalum rod. The interior supporting system helps prevent femoral head collapse.