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Measurement of Femoral Neck Anteversion

1957; Radiological Society of North America; Volume: 69; Issue: 2 Linguagem: Inglês

10.1148/69.2.209

1527-1315

Earl Budin, Elizabeth Chandler,

Hip and Femur Fractures

The purpose of this paper is to describe a direct method of measuring femoral neck anteversion, which is simple and accurate, eliminating the pitfalls of previous methods. The anatomy of the proximal end of the femur has in recent years received much attention because of the emphasis on early treatment of congenital dislocation. One of the more difficult studies has been evaluation of the degree of anteversion in normal and abnormal children. Although there was early recognition that this is best determined by a true axial projection of the femur, most of the reports state that the technical problem involved makes this direct method impractical. Considerable effort has been put forth by many authors, each devising an indirect method of varying complexity. The only report in the literature on the direct determination of this angle, to our knowledge, is that of Edgren and Laurent (6), who unfortunately deprecated the accuracy of the method. Definition The term anteversion has reference to the angle between the axis of the femoral neck and the coronal plane. The anteversion angle (Fig. 3,A) is often confused with the angle between the axis of the femoral neck and that of the femoral shaft as seen in the true lateral projection of the femur (Fig. 3,B). Although this latter angle has no correlation with the degree of anteversion, several methods of measuring it have been published which were intended to determine the extent of anteversion (2, 7, 10), in some cases specifically as an indication of the necessity for rotational osteotomy. Significance of Anteversion Many orthopedists feel that an abnormal degree of anteversion may preclude healing in congenital hip dislocation (9, 11), due to the inherent instability produced by the relationship of the femoral head to the acetabulum. It has also been suggested that this may be a factor in the etiology of the dislocation, but whether abnormal anteversion is a cause or a result is not yet known. In either event, there seems to be general agreement that congenital hip dislocations refractory to ordinary treatment should have rotation osteotomy if an abnormal degree of anteversion exists. The lack of agreement as to what degree of anteversion should be considered an indication for osteotomy is no doubt the result, at least in part, of previous difficulties in accurate measurement. When rotation osteotomy is performed for tibial torsion, for fractures healed in poor position, or for other deformities, measurement of anteversion would seem to be the best control available. It is not commonly known that increased anteversion is associated with slipped femoral epiphysis (1). Here, too, evaluation of anteversion can be important in procedures where fixation devices are to be inserted into the femoral neck.