Variation of Baumann's angle with age, sex, and side: implications for its use in radiological monitoring of supracondylar fracture of the humerus in children.

We examined 577 elbow radiographs of children aged 2-14 years attending an accident and emergency department prospectively over a 2-year period, and after excluding 7% with an effusion, fracture, or oblique view, we calculated Baumann's angle on the remainder. We grouped the radiographs by age, sex, and side, giving 52 groups with a minimum of 10 radiographs in each group. Baumann's angle was found to range from 64-82 degrees, mean 73.6 +/- 2 SD = 8.73 in boys; 69-81, mean 75.6 +/- 2 SD = 5.78 in girls; 64-82, mean 73.5 +/- 2 SD = 5.78 on the left; and 66-82, mean 73.7 +/- 2 SD = 7.47 on the right. Analysis of variance showed there was no significant difference in the mean comparing boys with girls at each age, left to right at each age in the boys or girls, and there was no increasing or decreasing trend over the years in either sex on each side.