Measurement of Subpubic Angle in Radiograph

Abstract

Introduction: Subpubic angle, an important parameter used for sex determination in the pelvis, is the angle between two inferior pubic rami below the symphysis pubis. This study was carried out to determine the subpubic angle among the individuals referred for pelvic and KUB radiographs in the department of Radiology and Imaging, Tribhuvan University, Teaching Hospital.Methods: Prospective cross-sectional study was done on 120 individuals. The subpubic angle was measured by drawing two tangent lines on the inferior border of the pubic rami. The subpubic angle of both sexes was measured. An independent sample t-test for equality of means was used to determine the difference between the two sexes regarding the subpubic angle. The correlation between the subpubic angle and the age of subjects was obtained using Pearson Correlation Coefficients in males and females.Results: The range of the subpubic angle in male was 82o to 122° and the mean was 104.72°±10.47°. In females, the range was 96o to 159° and the mean was 137.15°±11.92° with a significant statistical difference from the angle in male (p<0.05). The subpubic angle was not significantly correlated with age in males (r=0.029, p=0.824) whereas, in females, the correlation of subpubic angle with age was significant (r=-0.303, p=0.019).Conclusion: The mean subpubic angle was significantly wider in females than in males in this study. We found a weak negative correlation between subpubic angle and age in females whereas in the male there was no correlation between age and subpubic angle.

Mean Subpubic Angle of Patients Visiting Department of Radiodiagnosis of a Tertiary Care Hospital: A Descriptive Cross-sectional Study

“…The findings of the present study are comparable with that of Kayastha P, et al (SPA of male= 104.72±10.47°, SPA of female= 137.15±11.92°), who also attempted to determine the SPA using digital pelvic radiographs in the Nepalese population as in our study. 16 On the other hand, the SPA was considerable lower in other studies; 59.05±7.11° in males and 75.60±9.81° in females in a morphometric study performed on 40 adult dry articulated pelvis 1 and 68.6±7.6° in males and 87.4±6.5° in females in a study done in reconstructed threedimensional computed tomography pelvic model in a Malaysian population. 3 Discrepancies in SPA made by our study in comparison with other studies may be due to variation in the modalities adopted in measuring SPA and different ethnic groups.…”

“…SPA declines as people age. 16 Akhlaghi M, et al also noted a significant decrease in SPA with an increase in age in females. 19 However, Karakas HM, et al did not find any correlation between the SPA and age, 20 while Nwoha reported that the older individuals have lager SPA compared to the younger ones.…”

“…Khodeary, et al and Kayastha P, et al also found higher SPA (102.31±12.50° and 104.72±10.47° respectively) than the most accepted cut-off value in male. 15,16 Mohad Ali SH, et al discovered SPA in female was 87.4±6.5° using a threedimensional computed tomography model of the pelvis, which is less than the widely accepted cut-off value in female. 3 Hence, the sex determination using the cut-off value of 90° is not always accurate and may not be applicable to all the population.…”

“…Similar findings were observed in several other studies. 1,15,16 The subpubic concavity does not fully develop in females until they reach the age of 20 years. 8 As a result, there is no sexual dimorphism in the preadolescent pelvis.…”