Three-dimensional Computed Tomography Scan of the Pelvic Bone in Isolated Epispadias: Analysis Before Surgical Correction

Abstract

To determine intrapelvic angles and distances in pure epispadias patients and compare them to normal values. Using three-dimensional computed tomography, 17 intrapelvic dimensions (8 angles and 9 distances) were measured in 26 patients with pure epispadias (21 boys and 5 girls). These values were compared to normal values obtained from 6 patients (5 boys and 1 girl) who underwent either pelvic or abdominopelvic computed tomography for purposes unrelated to their bony pelvis. Significant differences were observed in five angles (sacroiliac joint angle, S1 tilt angle, sacral curvature, superior-inferior rotation of the pelvis, and pubococcygeal angle; P-value=.016, .044, .011, .020, and .001, respectively); these show less sacral rotation toward the axial plane, more sacral curvature, inferior rotation of the pelvis, and sacroiliac joints' rotation toward the coronal plane in epispadias compared to controls. Also, two distances (pubic diastasis and anterior segment length of the pelvis; P-value=.002 and .012, respectively) had significant differences, showing wider pubic diastasis and shorter anterior segment in epispadias. However, the differences between other intrapelvic angles and distances were not statistically significant between the two groups. In addition to the explanations hypothesized for the embryology of the exstrophy-epispadias complex, there can be other etiologies for both epispadias and bladder exstrophy to explain the differences between bony anatomies of the pelvis in these patients.