The Morphologic Study of the Calcar Femorale and its Relations to the Anteversion of the Neck of the Femur

Lee, Seung Won; Ha, Pil Seong; Kang, Jae Do; Kim, Jin Jeong

Abstract

The calcar femorale is a specific anatomic entity which is often confused with the medial trabecular system or posteromedial cortex of the neck of the femur. The clinical significance of its architecture is evident when one considers the great number of operative procerdures performed in the upper end of the femur. This study deals with 45 cases of the Korean Dry femur(male: 27, female: 12, useless: 6) and two pairs of the femur from the cadavers. The authors observed the three dimensional structure of the calcar femorale and studied the relation between anteversion and calcar femorale. The results obtained were as follows: 1. The calcar femorale was a vertical plate of the thickened bone that lay deep to the lesser trochanter. The length in the vertical axis of the calcar femorale was 44.82±3.59mm. The calcar femorale was thickest medially where it joins the medial trabecular system of the femoral neck (maximal thickness: 2.65±0.65, width: 8.90±1.82mm). 2. The calcar femorale lay in one plane, which inclined 30.02±7.80 degree to the discondylar axis of the femur. By using this inclination of the calcar plane, it could be best visualized with about 60° external rotation of femur in a simple X-ray. 3. The angle between the calcar plane and the diacondylar axis was proportionate to the anteversion of the femoral neck. Correlation coefficient(r=0.80) was calculated. The regression line of y (anteversion) on x(calcar angle) was y=0.75Xâˆ’8.53(slope). With this proportion, the angle of the femoral anteversion could be determined. 4. Microscopic features of the calcar femorale was revealed in the scanning electron microscopic studies. The medial side of the calcar was a cortical extension and it became thinner posterolaterally and than it was composed of fused or thickened trabeculae.