Objectives: To examine anatomic features in the pelvic bones and muscles in women with urinary incontinence (UI).
Material and methods: Between October 2005 and January 2006, 212 consecutive women underwent pelvic computerized tomography in our center. Preceding the examination, all women completed a clinical and demographic questionnaire including detailed questions about UI. Several anatomic parameters using multiplanar reformation and three-dimensional techniques (volume rendering) were examined. We specifically evaluated different bony parameters, pelvic floor muscle angles, densities, and cross-sectional areas. Ninety-three women (46.5%) had UI; the remaining women served as the control group. A logistic regression model was used to evaluate risk factors for UI.
Results: The mean age was 55.5 yr (range: 19-90). Women who suffered from UI were older (60.97 vs. 50.77 yr, p<0.0001), had higher body mass index (27.65 vs. 25.49, p<0.01), had more previous hysterectomies (21.5% vs. 6.5%, p<0.005), underwent more pelvic irradiation (9.7% vs. 1.8%, p<0.05), and had more diabetes mellitus (31.2% vs. 13.1%, p<0.005). Patient's age and previous hysterectomy were found to be the major clinical risk factors for UI (OR: 1.029, p=0.002; OR: 2.94, p=0.024, respectively). Logistic regression analysis on all clinical and morphologic variables yielded the following risk factors: pelvic-inlet diameter (OR: 1.216, p<0.0001), pelvic-inlet anterior-posterior diameter (OR: 1.109, p=0.003), pelvic-outlet diameter (OR: 1.077, p=0.011) and transverse perineal muscle cross-section diameter (OR: 0.773, p<0.0001).
Conclusions: Pelvic inlet and outlet dimensions are major risk factors for developing UI in women. These findings may lead to a better comprehension of the pathophysiology of UI in women.