Abstract
In this study, to clarify the usefulness of the plate, we performed pressure measurement for stems with and without a plate, andcompared the two types of stem using pressure distribution in the stem as a parameter.
Ten artificial femurs were modified so that the shape of the medullary cavity was the same as that of the external surface of the stem.The measurement system consisted of a computer for measurement control, I-SCAN, PCI interface board, tactile sensor sheet, and a sensorconnector. The tactile sensor sheet was applied between the artificial femur and stem, which was placed in the femoral stem stability tester. A load (650 N) was applied to the femoral head for 30 seconds, and stress distribution after loading in the medial-lateral and anterior-posteriordirections was quantified. Maximum values were presented as the results.
The results of measurement showed lower pressure for stems with than for those without a plate.
Therefore, we speculated that the plate absorbed and scattered the load applied on the femoral head, reducing pressure at the bone-steminterface, and also reduced radial pressure in the stem axis direction, preventing excessive pressure concentration through its micromotion.
