Collodiaphyseal angle in the diagnosis of coxa vara and coxa valga in adult Nigerans

Abstract

Collodiaphyseal angle (CDA) is the angle formed between the femoral neck axis and the diaphysis axis. The aims of this study were to determine the normal range of collodiaphyseal angle in adults and to determine any difference in the collodiaphyseal angle between right and left femur and also between sexes. 340 subjects consisting of 170 (50%) males and 170 (50%) females were included in this study. Plain radiographs were taken with the patients lying supine and the medial malleoli touching each other to prevent the hips being laterally rotated. Films were shot at a film focal distance (FFD) of 90 cm to minimize magnification. Measurements were taken with calibrated ruler and the collodiaphyseal angle was measured using goniometer. Results showed a normal range of CDA among Nigerian males as mean ± SD of (133.2° ± 7.6) for the right and mean ± SD of (131.1° ± 7.3) for the left. In females, it was (125.1° ± 6.9) on the right and (123.0° ± 6.9) on the left. Based on the study, coxa vara and coxa valga could be diagnosed on the normal range of collodiaphyseal angle in Ile-Ife (118° -145° in males and 110° -138° females). There is also sex variation and difference in CDA between right and left femur. Key words: Collodiaphyseal angle, coxa vara, coxa valga.