Association of Subpubic Angle Measurement with Age and Gender in a Group of Adult Sudanese Patients

Abstract

Background: The measurement of the subpubic angle (SPA) has been used for determining gender with a high degree of accuracy in various ethnic groups. This measurement can also be helpful in forensic and physical anthropology. The aim of this study was to compare the SPA in different adult age groups (males and females) and to use the SPA to estimate the demarking point (DP) for the determination of gender.
 Methods: This study included 158 subjects – 59 male and 99 female. The SPA was measured electronically using antero-posterior pelvis X-rays. Measurements were taken retrospectively using the Picture Archiving and Communication System. SPA measurements were compared between the male and female participants in different adult age groups. To determine the gender, the DP was calculated from the means of SPA in male and female participants. 
 Results: A comparison of the means of SPA between males and females showed that females (134.94 ± 15.33º) had wider SPA than males (105.88 ± 10.33) with a significant difference (P = 0.012). While a DP > 126.5 is most likely indicative of a female pelvis, a DP < 104.3 is indicative of a male pelvis. The accuracy levels based on the measured DP of participants in this study were 45.8% and 69.7% for males and females, respectively. Besides, with regards to age, the mean values for different age groups in males and females were statistically insignificant (P-values were 0.21 and 0.75, respectively). 
 Conclusions: According to the obtained results, the variations in the measurements of the SPA from pelvic X-rays can be used to determine gender. The calculated SPA range and DP were found to predict female gender with higher accuracy. Age was not associated with any notable differences in SPA measurements.
 Keywords: subpubic angle, pelvis, Sudanese, sex differences