Femoral Neck Axis Drawing with Two Parallel Lines in Asymptomatic Adults

Introduction: we are presentig and testing a method of femoral neck axis drawing with two parallel lines that do not depends of center of femoral head rotation which might be helpfull in measuring of paramethers in patients with femoral head tilt.

Goal of this study was to present and test a method of femoral neck axis drawing using two parallel lines and to compare it with a standard femoral neck axis drawing, named colo-capital femoral neck axis, in healthy asymptomatic pearsons of both sexes.

Methods: On the anteroposterior and lateral radiographs of the left and right hips of 78 examinee (286 hips alltogether), we have drown two femoral neck axes, one literaturs standard axis and secoond femoral neck axis drown with two parallel lines. On indexed axes we have drown, measured and compared alfa angle and offset index according with, in literature, proposed methods.

Results: We have found overlapping of the two drown axes in 60% on the anteroposterior hip images and in 67% on lateral hip images. The angle, marked γ, thay formed in the rest drown hips, had value 1-3°. There weren’t significant diference in the data values of alfa angle and offset index drown on indexed axes (p˃0,05), and also with, in the literature, accepted normal values of indexed parameters.

Conclusion: We have shown that using the method of two parallel lines of the medial third of the femoral neck, it is possible to draw the femoral neck axis, with the same validity as the most commonly used colo-capital axis of the femoral neck, with obvious advantage of the proposed method, since its drawing does not depend from the position of the femoral head and the position of the femoral head rotation center.

Keywords: femoral neck axis, drawing, two parallel lines, asimptomatic adults.