Functional anthropometric measurements of Indian pelvis

To determine the normal values of several radiographic measurements of hip and pelvis in individuals of Indian population.

We conducted a cross-sectional study of Indian population and calculated mean and variation seen in different parameters in Indian pelvis. We took the plain X-ray of randomly selected hundred patients in identical position with 20% magnification factor. Different parameters including acetabular inclination angle, cup size, tear drop position, neck shaft angle, neck offset, abductor lever arm and head size were drawn on the X-rays and values measured.

100 subjects were taken (63 male and 37 female). The mean of acetabular inclination angle was 37.70 ± 3.82° (30-47°). The mean neck shaft angle was131.53 ± 7.70° (114-158) the most commonly occurring value was 131°. The mean abductor lever arm was 38.48 mm ± 5.77 (23-54) with the mode of 40. The mean cup size was 48.9 ± 3.67 mm (34-58) with the most commonly occurring value as 50. The mean angle from tip of trochanter to center of head was 80.2 ± 9.1 (62-110). Among all the seven parameters correlations were drawn. There were in all 22 correlations out of which 14 were statistically significant.

Since there is significant difference between the neck shaft angles and other measurements of Indian population than to the European population, an evaluation in the design of the implant by the Indian manufacturers is recommended. Also this study proposes that the normal values of our own population be used as reference values in interpreting standard radiographs of pelvis with both hips.