Characterisation of pelvic types, inlet and outlet views using computed tomography in the Ugandan population

Abstract

Introduction Radiographic assessment of the pelvis requires AP, inlet and outlet views. The pelvic inlet and outlet views have traditionally been done at 45o cranially and caudally respectively. While these views have been perpendicular to each other, they may not be in the ideal to evaluate the pelvis. Evidence has shown variations in pelvic anatomy among races has affected the angulations required for these views. We hence sought to understand and define which angulations would be optimum in the Ugandan population. Objective To characterize the pelvic types, inlet and outlet views using Computed Tomography in the Ugandan population. Methodology Normal pelvic computed tomography scans were examined to identify those that fit the inclusion criteria until a total of 623 was achieved. They were then examined and the cranial, caudal angles measured using methods described by Ricci et al. The pelvic types were categorized using methods used by Naramuto et al. The information was then analyzed using STATA 15 with a comparative analysis between sexes, pelvic types and age. Results The most common pelvic type found was the gynaecoid type (57.8%). The precise angulation for assessment of the pelvic inlet in the Ugandan population is 27.40 ± 9.33 (95% CI: 26.65-28.14). The precise angulation for the pelvic outlet assessment is 70.83 ± 4.62 (95% CI: 70.47-71.19). There was no correlation between age, sex and pelvic inlet and outlet angles. The pelvic outlet angle was however affected by the pelvic type. F (3, 618) = 73.72, p=<0.001. (26.4% variance). Conclusions The most predominate pelvic type was the gynaecoid type. A cranial tilt of 27o and caudal tilt of 70o is recommended for the assessment of pelvic inlet and outlet radiographic views in the Ugandan population.