Radiographic Analysis of the Femur

Abstract

In revision surgery, four parameters are taken into consideration: the morphotype and the bone defects, but also the difficulties to excise the cement and the degree of osteoporosis. For each parameter a specific classification is established.

(1) Morphotype, evaluate the femur in the frontal and sagittal plane, two choices are possible: straight or curved femur. (2) Bone defects: evaluate all incidents that could have a weakening effect on the cortices and depending on their extent (according to zones of Gruen), classify into four stages. (3) Cement, evaluate the cement bed as a whole (a/p and lateral view) and take into account the quality of the cortices. The patients are classified into two groups, depending on whether difficulties to excise the cement are expected or not. (4) Osteoporosis, evaluate the thickness of the cortices and the geometry of the medullary canal and measure of the thickness of the cortices by a Cortical Index (CI), four stages can be identified.

These four parameters are classified in hierarchic order according to the imperatives imposed by the press-fit concept and, by combining, six Homogenous Radiographic Groups (HRG) can be identified.