Comparison of bony dimensions at the level of the pelvic floor in women with and without pelvic organ prolapse

Abstract

We sought to compare bony pelvis dimensions at the level of pelvic support in women with and without pelvic organ prolapse (POP). Pelvic floor dimensions of 42 white women with POP > 1 cm beyond the hymen were compared with 42 age- and parity-matched women with normal support. Bony landmarks relevant to connective tissue and levator attachments were identified on magnetic resonance imaging. Dimensions were independently measured by 2 examiners and averaged for each subject. Measurements (in centimeters) for patients and control subjects were as follows: interspinous diameter, 11.2 +/- 0.8 versus 11.1 +/- 0.7, P = .19; anterior-posterior outlet diameter, 11.7 +/- 0.7 versus 11.7 +/- 0.8, P = .71; pubic symphysis to ischial spine left, 9.5 +/- 0.5 versus 9.5 +/- 0.4, P = .91; pubic symphysis to ischial spine right, 9.5 +/- 0.4 versus 9.5 +/- 0.5, P = .81; sacrococcygeal junction to ischial spine left, 7.0 +/- 0.6 versus 7.0 +/- 0.5, P = .54; and sacrococcygeal junction to ischial spine right, 7.0 +/- 0.6 versus 6.9 +/- 0.4, P = .32. Bony pelvis dimensions are similar at the level of the muscular pelvic floor in white women with and without POP.