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BACKGROUND The plastic surgeon is often asked to reconstruct the sacral area related to pilonidal cysts or a tumor, or after other surgery, such as coccygectomy. When sitting pain is not due to the pudendal or posterior femoral cutaneous nerve injury, the anococcygeal nerve (ACN) must be considered. Clinically, its anatomy is not well known. Rather than consider coccygectomy when the traditional nonoperative treatment of coccydynia fails, resection of the ACN might be considered. METHODS A review of traditional anatomy textbooks was used to establish classical thoughts about the ACN. A retrospective cohort of patients with sitting pain related to the coccyx was examined, and those operated on, by resecting the ACN, were examined for clinicopathologic correlations. RESULTS When the ACN is described in anatomy textbooks, it is with varying distributions of innervated skin territory and nerve root composition. Most include an origin from sacral 5 and coccygeal 1 ventral roots. Most agree that the ACN forms on the ventral side of the sacrum/coccyx, alongside the coccygeus muscle, to emerge laterally and travel dorsally to innervate skin over the coccyx and lower sacrum. A review of 13 patients with sitting pain due to the ACN, from 2015 to 2019, demonstrated a mean age of 54.6 years. Eleven were female. The etiologies of ACN injury were falls (9), exercise (3), and complication from surgery (1). Six of the 9 patients who had surgery were able to be followed up with a mean length of 36.3 months (range, 11-63 months). Overall, 3 had an excellent result, 2 had a good result, and 1 was not improved. The one with a failed result showed improvement with coccygectomy. CONCLUSIONS The ACN must be included in the differential diagnosis of sitting pain. It is most often injured by a fall. The ACN can be evaluated with a diagnostic nerve block, can be identified at surgery, and can be resected, and its proximal end can be implanted into the coccygeus muscle. This surgery may prove an alternative to coccygectomy.

Background and Aim: Ultrasonography (USG) is useful for non-invasively identifying changes that occur in soft tissue architecture. The objective of this research was to demonstrate postpartum (PP) uterine involution through the changes of perineal muscle intensity and thickness in Madura beef cow by ultrasonography. Materials and Methods: Madura's breed cows used in the research consist of eight non-pregnant (NP) cows and three PP cow. The transrectal and transperineal USG imaging of NP cows was performed on days 1, 33, and 65. USG imaging of PP cows was performed every day starting from day 1 (24 h after parturition) until day 21 PP. Transrectal USG of the reproductive tract was performed for the cervix, corpus uteri, and cornua uteri. USG was performed transcutaneously over the perineal area for coccygeus and levator ani muscles at the longitudinal and transverse angles. Reproductive tract diameter and perineal muscle intensity and thickness were measured with ultrasound imaging. Results: The analysis of the sonogram of PP cows showed that the diameter of the cervix, corpus uteri, and cornua uteri decreased within 21 days PP. The transverse view of the coccygeus muscle of PP cows showed decreased muscle intensity and thickness. On the other hand, the longitudinal view showed increased coccygeus muscle intensity and thickness. The transverse view of the coccygeus muscle of NP cows showed increased muscle intensity, while muscle thickness was reduced. Sonogram analysis of the levator ani muscle of PP cows showed decreased muscle intensity with increasing muscle thickness. However, imaging of the levator ani muscle of NP cows showed a decrease in both intensity and muscle thickness. There was a significant difference in the mean value intensity of the scanning view analysis results of the levator ani muscle of the PP cow (523.6 AU increased to 672.1 AU) and the NP cow (515.9 AU decreased to 465.4 AU). Furthermore, there was a significant difference (p

Background: Pelvic organ prolapse affects half of vaginally parous women. Several animal models are used to study its pathophysiology and treatment. Sheep are interesting because they develop spontaneously prolapse with similar risk factors as women and can be used for vaginal surgery. This study describes ovine pelvis anatomy and compares it to women's pelvis to provide anatomical tools for translational researchers. Methods: MRI, pelvic dissections, and histology were used for detailed macro- and microscopic analysis of relevant anatomical structures in 6 nulliparous ewes. Results: Although sheep are quadrupeds, the gross and microscopic anatomies are similar to the female pelvis. Principal differences are the shape and its orientation, the absence of the sacrospinous ligament and the internal obturator. The levator ani (except for the puborectalis) and the coccygeus muscle are present, yet the latter is more developed - coinciding with the tail. The dimensions and morphology of the ovine vagina is comparable. The retropubic and the rectovaginal space are accessible transvaginally. There is a wide expression of estrogen receptors with low or absent immunoreactivity in the urethral epithelium, bladder, anus and internal anal sphincter. Conclusion: The ovine pelvic floor has many anatomical and ultrastructural similarities to the female pelvic floor.

The aim of this study was to explore the anatomical variations of the nerve to the levator ani (LA) and to relate these findings to LA dysfunction. One hundred fixed human female cadavers were dissected using transabdominal, gluteal, and perineal approaches, resulting in two hundred dissections of the sacral plexus. The pudendal nerve and the sacral nerve roots were traced from their origin at the sacral foramina to their termination. All nerves contributing to the innervation of the LA were considered to be the nerve to the LA. Based on the spinal nerve components, the nerve to the LA was classified into the following categories: 50% (n = 100) originated from S4 and S5 (type I); 19% (n = 38) originated from S5 (type II); 16% (n = 32) originated from S4 (type III); 11% (n = 22) originated from S3 and S4 (type IV); 4% (n = 8) originated from S3, S4, and S5 (type V). Two patterns of nerve termination were observed. In 42% of specimens, the nerve to the LA penetrated the coccygeus muscle and assumed an external position along the inferior surface of the LA muscle. In the remaining 58% of specimens, the nerve crossed the superior surface of the coccygeus muscle and continued along the superior surface of the iliococcygeus muscle. Damage to the nerve to LA has been associated with various pathologies. In order to minimize injuries during surgical procedures, a thorough understanding of the course and variations of the nerve to the LA is extremely important.

An analysis of the literature has allowed for a redefinition of the anatomy of the ilio-coccygeus muscle (ICM) its insertions and its trajectory, the direction of its fibers and its relation to the base of the bladder. Static MRI studies have revealed its V-shaped appearance, while dynamic MRI has been used to visualize its concave contraction into a dome-shape that provides support to the levator plate, raising the base of the bladder. Histological studies have shown that the percentage of type I muscle fibers is 66% to 69%, which is comparable to the type I fiber content of the pubovisceral muscle (PVM), thus reflecting both its postural role as well as functions based on frequent voluntary contractions. Together, these data suggest an active role for the ICM which, upon urination, allows for voluntary hardening of the levator plate. The abdominal pressure from bearing down hence enables urinary draining by compressing the bladder on a hard surface. The physiological function of the ICM is therefore not only postural, but also to enable urination. From a therapeutic perspective, a multicentric study has shown that, by reinforcing the action of the ICM, use of a Diveen intrauterine device improved dysuria.

Knowledge of female pelvic anatomy helps the clinician recognize correctly childbirth trauma and manage it accordingly. This chapter presents aspects of the anatomy of abdominal wall, external and internal genital organs, anal sphincter and pelvic muscles, including levator ani. The vulva consists of mons pubis, clitoris, hymen, labia minora and majora, vestibule and urethral meatus. The vagina is a virtual cavity between the bladder anteriorly and rectum posteriorly, a musculo-membranous organ that connects the vulva and the uterus. The muscles of the external female genitalia are formed by pelvic muscles and cavernous bodies (ischiocavernosus and bulbocavernosus). The pelvic diaphragm that supports the pelvic load is formed by the levator ani muscle (pubovaginalis, pubourethralis, puborectalis and iliococcygeus muscles) and the coccygeus muscle. The anal sphincter is formed by the external and internal anal sphincter, with different structures and function.

Aims The aim was to develop a new laparoscopic technique for placement of a pudendal lead. Methods Development of a direct, feasible and reliable minimal-invasive laparoscopic approach to the pudendal nerve (PN). Thirty-one embalmed human specimens were dissected for the relevant anatomic structures of the pelvis. Step-by-step documentation and analysis of the laparoscopic approach in order to locate the PN directly in its course around the medial part of the sacrospinous ligament and test this approach for feasibility. Landmarks for intraoperative navigation towards the PN as well as the possible position of an lead were selected and demonstrated. Results The visible medial umbilical fold, the intrapelvine part of the internal pudendal artery, the coccygeus muscle and the sacrospinous ligament are the main landmarks. The PN traverses the medial part of the sacrospinous ligament dorsally, medially to the internal pudendal artery. The medial part of the sacrospinous ligament has to be exposed in order to display the nerve. An lead can be placed ventrally on the nerve or around it, depending on the lead type or shape. Conclusions A precise and reliable identification of the PN by means of laparoscopy is feasible with an easy four-step approach: (1) identification of the medial umbilical fold; (2) identification of the internal iliac artery; (3) identification of the internal pudendal artery and incision of the coccygeus muscle ('white line', arcuated line); and (4) exposition of the medial part of the sacrospinous ligament to display the PN.

Objectives The contributions of the pudendal and levator ani nerves to the innervation of the levator ani muscle (LAM) are disputed. Because of the relatively large size of the nerves in early life, we investigated this issue in human fetuses. Methods (Immuno)histochemically stained serial sections of nine human fetuses (9–22 wk of gestation) were investigated. Both the left and right sides of the fetal pelves were studied individually and 3D reconstructions were prepared. Results The levator ani nerve innervated the LAM in every pelvis, whereas a contribution of the pudendal nerve to the innervation of the LAM could be demonstrated in only 10 pelvic halves (56%). In 10 halves, we observed a communicating nerve branch between the pudendal and levator ani nerves that pierced the pelvic floor between the LAM and the coccygeus muscle. No sex differences were observed, but the innervation pattern did differ between the left and right side of a pelvis. Conclusions The LAM often has a dual somatic innervation with the levator ani nerve as its constant and main neuronal supply.

Aims To compare the histomorphology of pelvic floor specimens of 94 female cadavers, ten male cadavers, and 24 female symptomatic patients who underwent pelvic floor surgery, and to evaluate the association of age, parity, and sex to myogenic and/or neurogenic changes to the levator ani muscle (LAM). Methods The pelvic floor was biopsied at the pubococcygeus, the iliococcygeus and the coccygeus muscle. After staining, signs for myogenic/neurogenic changes to the muscle were evaluated (fibrosis, variation in fiber diameter, centralization of nuclei, small angulated fibers, and type grouping). To identify the intact neuromuscular junction stainings with NCAM (neuronal cell adhesion molecule) and acetylcholinesterase (ACE) were used. Results A significant influence of age and parity on the histomorphological criteria of myogenic cell-damage was shown in this study. Although these criteria were found even in young nulliparous women, there was a significant increase in older or parous women with at least one vaginal delivery. We failed to demonstrate significant changes between the nulliparous LAM, the male LAM, and the LAM from women with prolapse and incontinence. None of the specimen showed any obvious evidence of neuropathy. Conclusions We have evaluated histological criteria adapted from the examination of limb muscles in the LAM of nulliparous young women. “Myogenic changes” seem to be a normal finding in the LAM. The increase of these changes with aging and parity points to mechanical stress to the LAM as the most plausible causative factor. We propose that further studies using histomorphological techniques of the pelvic floor muscle in nulliparous and parous women should clarify the potential role of our histological findings. © 2004 Wiley-Liss, Inc.

Background The integrity of the pelvic autonomic nervous system is essential for proper bowel, bladder, and sexual function. Objective The purpose of this study was to characterize the anatomic path of the pelvic autonomic system and to examine relationships to clinically useful landmarks. Study Design Detailed dissections were performed in 17 female cadavers. Relationships of the superior hypogastric plexus to aortic bifurcation and midpoint of sacral promontory were examined; the length and width of plexus was documented. Path and width of right and left hypogastric nerves were recorded. The origin and course of the pelvic splanchnic nerves were documented. Individual nerve tissue that contributed to the inferior hypogastric plexus was noted. Relative position of nerves to arteries, viscera, and ligaments was documented. In a subset of specimens, biopsy specimens were obtained to confirm gross findings by histologic analysis. Descriptive statistics were used for data analyses and reporting. Results In all specimens, the superior hypogastric plexus was embedded in a connective tissue sheet within the presacral space, just below the peritoneum. In 14 of 17 specimens (82.4%), the plexus formed a median distance of 21.3 mm (range, 9–40 mm) below aortic bifurcation; in the remaining specimens, it formed a median distance of 25.3 mm (range, 20.5–30 mm) above bifurcation. In 58.8% of specimens, the superior hypogastric plexus was positioned to the left of midline. The median length and width of the plexus was 39.5 (range, 11.5–68) mm and 9 (range, 2.5–15) mm, respectively. A right and left hypogastric nerve was identified in all specimens and formed a median distance of 23 mm (range, 5–32 mm) below the promontory. The median width of the hypogastric nerve was 3.5 mm (range, 3–4.5 mm) on the right and 3.5 mm (range, 2–6.5 mm) on the left. The median distance from midportion of uterosacral ligament to the closest nerve branch was 0.5 mm (range, 0-4.5 mm) on right and 0 mm (range, 0-27.5 mm) on left. In all specimens, the inferior hypogastric plexus was formed by contributions from the hypogastric nerves and branches from S3 and S4. In 47.1% of hemipelvises, S2 branches contributed to the plexus. The sacral sympathetic trunk contributed to the plexus in 16 of 34 hemipelvises where this structure was identified. The inferior hypogastric plexus formed 1–3 cm lateral to the rectum and upper third of the vagina. From this plexus, 1–3 discrete branches coursed deep to the ureter toward the bladder. A uterine branch that coursed superficial to the ureter followed the ascending branch of the uterine artery. An S4 branch was found directly attaching to lateral walls of the rectum in 53% of specimens. Pelvic splanchnic nerves merged into the inferior hypogastric plexus on the lower and medial surface of the coccygeus muscle. Histologic analysis confirmed neural tissue in all tissues that were sampled. Conclusion Anatomic variability and inability to visualize the small caliber fibers that comprise the inferior hypogastric plexus grossly likely underlines the reasons that some postoperative visceral and sexual dysfunction occur in spite of careful dissection and adequate surgical technique. These findings highlight the importance of a discussion with patients about the risks that are associated with interrupting autonomic fibers during the preoperative consent.

Fertility ratio is defined here as the proportion of females that a male can impregnate after a constant period of in-polygyny living. This ratio was investigated in male rats after denervation of two pelvic floor muscles, the pubococcygeus and iliococcygeus. Denervation was carried out by transecting the somatomotor branch of the pelvic nerve. The lesion did not modify the sexual behavior of males or their overall fertility, but decreased the weight of the ejaculated seminal plug. Consequently, the number of days living in cohabitation to induce pregnancy was increased in lesioned males (∼13 days) compared with intact and sham animals (∼5 days). These results showed that the fertility ratio was optimal when intact/sham males cohabited with females for two consecutive estrous cycles, but that lesioned males needed up to four cycles to induce most pregnancies. Two hypotheses are raised by our results. The first is that pelvic floor denervation decreases the forceful tension required to expel the semen from the prostatic urethra to the vagina, then an incomplete seminal plug is expelled. The second is that denervation cut afferent fibers that reflexively promote the continence of the semen deposited in the prostatic urethra during seminal emission, allowing some to leak out before ejaculation. The latter hypothesis can also explain the recovery of the fertility ratio in lesioned males. It could be a compensatory mechanism mediated by the pudendal nerve supply to the coccygeus muscle, the other pelvic floor muscle.

A sexually intact, male Chihuahua and a spayed female poodle were presented with left perineal masses. The masses were identified as perineal hernias by rectal palpation. Surgical exploration of the perineal region in each dog revealed retroperitoneal fat protruding between the sacrotuberous ligament and the coccygeus muscle (sciatic perineal hernia). The hernias were repaired using modifications of the standard or internal obturator flap herniorrhaphies. The levator ani muscle was grossly and histologically normal in the Chihuahua and grossly normal in the poodle. No short- or long-term complications were reported in either case. The management of sciatic perineal hernia is similar to the more common caudal perineal hernia.

Despite all publications on different muscles present within the pelvic diaphragm, development shows that there are only two: the levator ani muscle and the coccygeus muscle. The extended description given is needed to contradict literature. The pelvic diaphragm does not contain gender differences. A nearly philosophical question is paired and unpaired construction of pelvic organs, demonstrated by development of the urogenital system and pelvic sphincters. Anal sphincter development is treated together with anorectal malformations. Attention is given to placodes, neural crest development, and the development of pelvic brain centers.

As a result of the pioneering research undertaken by physiotherapists in Australia (Wohlfahrt and Jull, 1993; O’Sullivan et al., 1997; Richardson et al., 1999) clinical professionals working in the area of musculoskeletal dysfunction have become increasingly aware of the crucial importance of what may be called the ‘‘Deep Stabilization system’’. Even before this our attention was indirectly drawn to the same problem by Silverstolpe’s findings (Silverstolpe, 1989). This author demonstrated that on snapping-palpation of highly active trigger points (TrPs) of the thoracic erector spinae, extension of the lumbar spine and pelvis was obtained, by contraction of the lumbar erector spinae. This has been confirmed by electromyography (EMG) (Skoglund, 1989). Concomitantly, a pain point is identified with palpation of the sacrotuberous ligament. Following massage of this pain point, the TrP in the spinal erector and the tender point in the buttocks and a whole chain of other symptoms vanished. In honor of Silverstolpe and Skoglund this whole complex is called the ‘‘S’’ reflex (Fig. 1). Not only was it possible to confirm Silverstolpes’ findings, but it was soon noted that it was possible to obtain release by mere pressure in the same direction. This, however, is a characteristic for a muscular TrP. Therefore it was concluded that this phenomenon was due to a TrP of the underlying coccygeus muscle, part of the pelvic floor. Learning how to relax the coccygeus muscle soon proved that it was indeed the pelvic floor. This became a clinical priority, because, however effective the treatment by massage and/or pressure was, the clinical complaints had a tendency to recur at very short intervals, and treatment was very unpleasant.

Background Reported rates of gluteal pain after sacrospinous ligament fixation range from 12–55% in the immediate postoperative period and from 4–15% 4–6 weeks postoperatively. The source of gluteal pain often is attributed to injury to the nerve to levator ani or pudendal nerve. The inferior gluteal nerve and other sacral nerve branches have not been examined thoroughly as potential sources of gluteal pain. Objectives The purpose of this study was to further characterize anatomy of the inferior gluteal nerve and other nerves that are associated with the sacrospinous ligament from a combined gluteal and pelvic approach and to correlate findings to sacrospinous ligament fixation. Study Design Dissections were performed in female cadavers that had not been embalmed with gluteal and pelvic approaches. From a pelvic perspective, the closest structure to the superior border of the sacrospinous ligament midpoint was noted, and the sacral nerves that perforated the ventral surface of coccygeus muscle were examined. From a gluteal perspective, the closest distances from ischial spine to the pudendal, inferior gluteal, posterior femoral cutaneous, and sciatic nerves were measured. In addition, the closest distance from the midpoint of sacrospinous ligament to the inferior gluteal nerve and the origin of this nerve were documented. The thickness and height of the sacrospinous ligament at its midpoint were measured. Sacral nerve branches that coursed between the sacrospinous and sacrotuberous ligaments were assessed from both a pelvic and a gluteal approach. Descriptive statistics were used for data analysis. Results Fourteen cadavers were examined. From a pelvic perspective, the closest structure to the superior border of sacrospinous ligament at its midpoint was the S3 nerve (median distance, 3 mm; range, 0–11 mm). Branches from S3 and/or S4 perforated the ventral surface of coccygeus muscles in 94% specimens. From a gluteal perspective, the closest structure to ischial spine was the pudendal nerve (median distance, 0 mm; range, 0–9 mm). Median closest distance from inferior gluteal nerve to ischial spine and to the midpoint of sacrospinous ligament was 28.5 mm (range, 6–53 mm) and 31.5 mm (range, 10–47 mm), respectively. The inferior gluteal nerve arose from dorsal surface of combined lumbosacral trunk and S1 nerves in all specimens; a contribution from S2 was noted in 46% of hemipelvises. At its midpoint, the sacrospinous ligament median thickness was 5 mm (range, 2–7 mm), and its median height was 14 mm (range, 3–22 mm). In 85% of specimens, 1 to 3 branches from S3 and/or S4 nerves pierced or coursed ventral to the sacrotuberous ligament and perforated the inferior portion of the gluteus maximus muscle. Conclusions Damage to the inferior gluteal nerve during sacrospinous ligament fixation is an unlikely source for postoperative gluteal pain. Rather, branches from S3 and/or S4 that innervate the coccygeus muscles and those coursing between the sacrospinous and sacrotuberous ligaments to supply gluteus maximus muscles are more likely to be implicated. A thorough understanding of the complex anatomy surrounding the sacrospinous ligament, limiting depth of needle penetration into the ligament, and avoiding extension of needle exit or entry point above the upper extent of sacrospinous ligament may reduce nerve entrapment and postoperative gluteal pain.

A thorough insight into the female genital anatomy is crucial for understanding and performing pelvic reconstructive procedures. The intimate relationship between the genitalia and the muscles, ligaments, and fascia that provide support is complex, but critical to restore during surgery for correction of prolapse or aesthetic reasons. The external female genitalia include the mons pubis, labia majora and minora, clitoris, vestibule with glands, perineal body, and the muscles and fascia surrounding these structures. Through the perineal membrane and the perineal body, these superficial vulvar structures are structurally related to the deep pelvic muscle levator ani with its fascia. The levator ani forms the pelvic floor with the coccygeus muscle and provides vital support to all the pelvic organs and stability to the perineum. The internal female genital organs include the vagina, cervix, uterus, tubes, and ovaries with their visceral fascia. The visceral fascia also called the endopelvic fascia, surrounds the pelvic organs and connects them to the pelvic walls. It is continuous with the paraurethral and paravaginal fascia, which is attached to the perineal membrane. Thus, the internal and external genitalia are closely related to the muscles and fascia, and work as one functioning unit.

This study was designed to describe the surgical anatomy and histology of the rabbit anorectum comparing it to that of humans, in order to decide whether it can be a good experimental model for research in proctology.This study of the anorectal region was performed on six female New Zealand white rabbits, weighting between 2.5-2.9 kg. An autopsy was performed immediately after sacrificing the animal and an anatomical and histological description was performed.The mean rectum and anal canal lengths were of 7.2 cm and 0.9 cm, respectively. The macroscopic study showed that the musculature of the anal canal is formed by the coccygeus muscle, which serves as puborectalis in humans. It also defined an external anal sphincter with a deep and superficial portion. The histological evaluation showed similarity to that of humans, with mucosa of simple columnar type, muscularis mucosae, a small submucosa, with a muscular wall divided into internal and external layers, separated by the myenteric plexus.The great similarity to both the anatomy and the histology of humans, appropriate size and easy-handling and care, make the rabbit an attractive animal for the use as experimental and research model in proctology.

In contrast to the attachments to the pubis and rectum, there is little information on fetal development of the coccygeal attachment of the levator ani muscles. We find that at 9 weeks, the coccygeus muscle is a large muscle facing the piriformis or gluteus maximus and inserting onto the ischial spine, whereas the levator ani is restricted to the area near the pubis. By 12 weeks, the levator ani also obtains attachment to the ischial spine immediately ventral to the coccygeus muscle. The most superior part of the coccygeus muscle occupies a space at an angle between the pelvic splanchnic and pudendal nerves. Notably, medial to the coccygeus muscle, a third parasagittal muscle (previously termed the sacrococcygeus anterior) appears by 12 weeks, increases in mass by 18 weeks, and connects and mixes with the dorsal end of the levator ani by 18–20 weeks. Thus, the coccygeal attachment of the levator ani appears not to depend on the dorsal extension of the muscle itself but on fusion with the sacrococcygeus anterior. Therefore, the final levator sheet is formed medial (internal) to the coccygeus muscle and originates from two distinct anlage. Clin. Anat. 23:566–574, 2010. © 2010 Wiley-Liss, Inc.

The female pelvic floor comprises several structures, including anal and urethral sphincters, several anatomical layers, and supportive elements (often constituents of the endopelvic fascia which is an advential layer). The multilayered urethra is supported by several structures such as the endopelvic fascia, compressor urethra, and urethrovaginal sphincter, and has attachment to the pelvic diaphragm. The uterus and vagina are, amongst other, supported by several condensations of the endopelvic fascia (e.g. the uterosacral ligament). The rectum is also supported by endopelvic fascia condensations. The anal sphincter is a multilayered cylindrical structure with an outer striated muscle (external sphincter, puborectal muscle). The perineal body has attachments with multiple structures such as the external sphincter, longitudinal layer, and perineal membrane and therefore has an important role in support. The major constituents of the pelvic diaphragm are the iliococcygeus and pubococcygeus muscles (both part of the levator ani muscle) and the coccygeus muscle.

Publisher Summary This chapter discusses the relevant anatomy, followed by common features of uroneurophysiological testing. Pelvic floor usually refers to the total layer closing the bony pelvic outlet—that is, the sum of the layers, the most cranial being the peritoneum and the most caudal being the skin of the perineum; the middle layers are predominantly muscle, usually referred to as “pelvic floor muscles.” Contrary to the usage of the term “pelvic floor muscles,” anatomists discern the “muscles of the pelvis” (levator ani, being subdivided into several parts—pubococcygeal, puborectal, iliococcygeal, iliosacralis—and the coccygeus muscle), and the “muscles of the perineum” (muscle of the anal triangle—the external anal sphincter; and muscles of the urogenital triangle—sphincter urethrae, transversus perinei, bulbocavernosus, ischiocavernosus, and in the female, in addition, the compressor urethrae and the urethrovaginal sphincter). The external anal sphincter is usually described as being composed of three parts (a subcutaneous part, a superficial, and a deep part—the latter merging into the puborectalis). The chapter concludes with individual tests described and critically evaluated.

A new ligature carrier designed for sacrospinous colpopexy permits bite acquisition to be performed under direct surgical visualization within the confines of the pararectal space. In addition, it permits ample penetration of the sacrospinous ligament through the coccygeus muscle, without restriction of suture type, size, or number of sutures per bite. As part of site-specific reconstructive pelvic surgery, we have performed sacrospinous colpopexy using this ligature carrier in 71 patients with genital prolapse. We have encountered no operative complications from the use of this ligature carrier.

Purpose: To provide quantitative data by a modern cross-sectional imaging technique (CT) for defining normal physiological values of pelvic floor structures. Patients and methods: Twenty seven subjects, 7 males, 20 females, aged 20 – 75 yrs (mean 46.3±5 yrs) without pelvic floor or defecation dysfunction underwent Direct Coronal (DC) CT scanning of the pelvis with the patient seated instead of lying. Scans obtained at rest and on straining were compared by bony landmarks. Three anatomical compartments, i. e. anterior, middle and posterior, were identified by two planes drawn tangential to the ischial for-amina and the ischial tuberosities, respectively. Measurements of (1) Levator ani muscle length (mm); (2) Levator-anal angle (degrees); (3) Rectal floor-to-ischial line distance (mm) and (4) Supra/Infralevator spaces (square cm) were independently performed twice by two radiologists. The statistical analysis included calculation of intra and interobserver agreement (correlation coefficient). The differences between the means of the resting and straining values from each compartment (Student's t test) and the correlation between parameters (Pearson's coefficient) to evaluate whether resting values allowed a prediction of those on straining were determined. Results: DC scans of diagnostic quality were obtained in all but two patients (92.5%). Both intra- and interobserver agreement indices were always greater than 80% (except for a 0.63 value by one observer obtained in the infralevator space from the anterior compartment at rest). A significant difference between the resting and straining values of all parameters was noted in the three compartments. At rest the levator ani muscle length was significantly shorter and the supralevator space smaller in the posterior compartment (48.3±7.9 mm vs 48.8±7 mm vs 42.6±9.4 mm, P

The supinator muscle originates from the annular ligament of the radius, and the muscle fibers and ligament take a similar winding course. Likewise, the coccygeus muscle and the sacrospinous ligament are attached together, and show a similar fiber orientation. During dissection of adult cadavers for our educational curriculum, we had the impression that these ligaments grow in combination with degeneration of parts of the muscles. In histological sections of 25 human fetuses at 10-32 weeks of gestation, we found that the proximal parts of the supinator muscle were embedded in collagenous tissue when the developing annular ligament of the radius joined the thick intermuscular connecting band extending between the extensor carpi radialis and anconeus muscles at 18-22 weeks of gestation, and the anterior parts of the coccygeus muscle were surrounded by collagenous tissue when the intramuscular tendon became the sacrospinous ligament at 28-32 weeks. Parts of these two muscles each seemed to provide a mold for the ligament, and finally became involved with it. This may be the first report to indicate that a growing ligament has potential to injure parts of the "mother muscle," and that this process may be involved in the initial development of the ligament.

INTRODUCTION Rectovaginal fistula (RVF) is a rare but debilitating complication of a variety of pelvic surgical procedures. PRESENTATION OF CASE We report the case of a 45-year-old female who underwent the STARR (Stapled Trans Anal Rectal Resection) procedure, that was complicated by a 30mm rectovaginal fistula (RVF). We successfully repaired the fistula by trans-perineal approach and pubo-coccygeus muscle interposition. Seven months later we can confirm the complete fistula healing and good patient's quality of life. We carefully describe our technique showing the advantages over alternative suturing, flap reconstruction or resection procedures. DISCUSSION This technique is fairly easy to perform and conservative. The pubo-coccygeus muscle is quickly recognizable during the dissection of the recto-vaginal space and the tension-free approximation of this muscle by single sutures represents an easy way of replacement of the recto-vaginal septum. CONCLUSION In our experience the use of pubo-coccygeus muscle interposition is an effective technique for rectovaginal space reconstruction and it should be considered as a viable solution for RVF repair.

Muscles of the perineal region were dissected in 20 cats. Levator ani muscle was composed of two parts: iliocaudalis and puboischiocaudalis; both parts inserted entirely on caudal vertebrae, as did the coccygeus muscle. A well developed band of smooth muscle, the pars analis of retractor penis (clitoridis), inserted on the anal canal to retract the anus. The external anal sphincter had pars caudalis and pars cranialis divisions, the latter covered paired anal sacs. In addition, a distinct sphincter encircled each anal sac duct. In the male, levator scroti muscle originated from external anal sphincter. There was no continuity between external anal sphincter and bulbospongiosus muscles. Cremaster muscles were absent in the cat. In the female, pars cranialis of external anal sphincter gave origin to the constrictor vestibuli muscle, and pars caudalis to constrictor vulvae muscle. Bulboglandularis muscles were present in both sexes. Urethralis, ischiourethralis, and ischiocavernosus muscles in the cat were similar to other quadripeds.

The efferent innervation of the pelvic and pudendal nerves was characterized in this study by identifying the muscles activated by electrical stimulation of the nerves distal to the point at which they bifurcate from the L6-S1 trunk. Pelvic nerve electrical stimulation produced EMG-monitored contraction of the ipsilateral ilio- and pubococcygeus muscles, which was abolished by cutting one ('muscular') branch of the bifurcated nerve. (This 'muscular' branch receives proprioceptive input activated by tail displacement, whereas the other, 'viscero-cutaneous' branch receives sensory innervation from the midline perineal region.) Pudendal nerve electrical stimulation produced contraction of the coccygeus, external anal sphincter, and ischiocavernosus muscles. Movements of the orifice and wall of the vagina were directly visualized during electrical stimulation of the two nerves. Intravaginal pressure measured by balloon was increased by pelvic nerve stimulation and decreased by pudendal nerve stimulation. Reflexive contraction of the ilio- en pubococcygeus muscles was produced by mechanostimulation of the perineum, clitoral sheath and distal vagina. This response was abolished by gentle cervical mechanostimulation. One implication of this finding is that passage of the fetuses through the cervix during parturition may relax the ilio- and pubococcygeus muscles, thereby facilitating delivery.

Dear Editor: With great interest, I read the recent publication of Dietz et al. [1] in your journal. The authors describe that buttock pain occurred post-operatively in ~18% of patients undergoing sacrospinous hysteropexy for pelvic organ prolapse. The authors state in their discussion that the pain can be explained by injury to nerves of the sacral plexus, such as the branches of the pudendal nerve. In this letter, I would like to propose that this pain can be explained by injury of the ‘levator ani nerve’, the nerve that lies on the superior surface of the sacrospinous ligament and in the area of the operative field. This explanation has been neglected in clinical studies so far. Recent research by our group [2, 3] and others [4–8] has emphasized that the levator ani muscle is innervated not only by the pudendal nerve from its inferior surface but also by the levator ani nerve from its superior surface. The levator ani nerve originates directly from the sacral plexus and courses on the superior surface of the coccygeus muscle/sacrospinous ligament complex towards the superior surface of the levator ani muscle (Fig. 1). On its trajectory, it crosses the sacrospinous ligament 0–4 cm medial to the ischial spine [2, 6–8]. As sutures are placed through the sacrospinous ligament approximately 2 cm medial to the ischial spine during sacrospinous hysteropexy or sacrospinous ligament fixation in general, the procedure can injure the levator ani nerve [2, 5–8] and thereby entail the sensation of buttock pain. Additional injury to the pudendal nerve may also occur because the pudendal nerve, which lies inferior to the sacrospinous ligament, is only 4–11 mm apart from levator ani nerve [2]. Int Urogynecol J (2008) 19:1729–1730 DOI 10.1007/s00192-008-0646-3