The ratio of femoral head diameter to pelvic height in the normal hips of a Chinese population

Objective

The aim of this study was to determine whether the ratio between the femoral head diameter and pelvic height in a Chinese population is the same as that found in Westerners.

Materials and methods

Standard pelvic radiography was performed on a group of 187 Chinese adult subjects consisting of 81 males and 106 females with a mean age of 40 years (21–68 years). Femoral head diameter (vertical distance from the femoral head–neck junction to the highest point of the femoral head) and pelvic height (vertical distance from the highest point of the iliac crest to the edge of the ischial tuberosities) were measured.

Results

There were significant differences between males and females (p < 0.001), and between persons of high height versus low height (p = 0.011) and medium height (p = 0.039). There were no significant differences between persons of different age (p = 0.244), body mass index (p = 0.091), or between persons of low- and medium-height groups (p = 0.69). The overall mean ratio between the femoral head diameter and pelvic height was 0.215 (0.173–0.249) with a 95 % CI = 0.214–0.217. The mean ratios in males and females were 0.221 (0.194–0.249) and 0.211 (0.173–0.238), respectively.

Conclusion

The mean ratio in Chinese population was similar to the reported ratio in a western population (about 1:5). We suggest that Chinese surgeons may be able to use the Crowe classification to classify patients with hip dysplasia.