THE SUB-PUBIC ANGLE IN ADULT INDIGENOUS MALAWIAN SUBJECTS

Abstract

Background: A number of parameters are used to assess the pelvis for clinical, physical and forensic anthropological reasons. When it is adequately assessed within any population group, the pelvis displays wide variations. Although the sub-pubic angle is one of the three forensically important angles of the pelvic outlet, literature is scanty or lacking on East and Central Africans, and no published report is available on indigenous Malawian subjects.
Objectives: To determine the sub-pubic angle in indigenous Malawians and compare them with angles from other population groups previously reported.
Design: A cross-sectional study.
Setting: Queen Elizabeth Central and Blantyre Adventist hospitals in the city of Blantyre.
Subjects: One hundred and nineteen antero-posterior radiographs of pelves of adults indegenous Malawians aged 20-84 years to determine their sub-pubic angle.
Results: Women showed significantly wider sub-pubic angles than men (129.07 ± 14.19° SD women and 99.16 ± 15.73° SD men; P < 0.001), confirming similar results previously studied in other population groups. We have demonstrated that the sub-pubic angle alone could accurately assign sex to 67.12% of males and 63.04% of females, and race could be accurately assigned to 21.92% of men and 89.96% of females. Malawians
showed significantly wider angles than Amerindians, Black and White Americans (P < 0.001).
Conclusion: This study documents sexual and racial differences and for the first time (on comparison) the sub-pubic angles indicate geographical variations, underpinning the need to establish normal ranges of these angles in any given population. We recommend the establishment of local references of the sub-pubic angle to other countries in the sub-region.