The structural anatomy of the female pelvic floor: Syme Surgical Fellowship

The Pelvic Floor can be differentiated into a Pubic and Sacral Segment, contrasted as follows :—PUBIC SEGMENT. Loose in its attachments. Drawn up during labour. Driven down in prolapsus uteri. Passes down with viscera in genu-pectoral posture, when vagina is distended by air, and is therefore intestinal.SACRAL SEGMENT: Firm in its attachments. Driven down during labour. Always remains in position (posterior vaginal wall excepted) in prolapsus uteri. Remains in position in genu-pectoral posture, with vagina distended by air, and is therefore vertebral.Three vertical "lines of cleavage" exist in the pelvic floor :— 1. Vaginal, i.e., between vaginal walls. All in front is drawn up in labour, and goes down with viscera in genu-pectoral posture ; all behind is driven down during labour, and remains in situ in genu-pectoral posture after vagina is distended with air. (Figs. 4 and 5.); 2. Recto-vaginal\ between anterior wall of rectum and posterior wall of vaginar All in front comes down in prolapsus uteri; all behind remains in situ} (Fig. 10.); 3. Rectal, between the anterior and posterior walls of rectum. All in front of this is lifted up in the " bimanual," and when rectum is distended with air. (Fig. 19.)The first line is therefore the physiological line of cleavage, the second is the pathological, and the third the instrumental. (Fig. 22.) The Sims speculum pulls back the sacral segment, while, by posture of patient, the pubic segment sags down.The Hodge and ring pessaries are kept in position by the pubic segment pressing them against the oblique sacral one. In retroversion of the uterus, and in prolapsus uteri, they keep the posterior vaginal wall its proper length and render it rigid, so that it runs round the top bar of the pessary like a pulley, and is reflected down on the cervix making it tense. It thus pulls the cervix back and keeps it so