The Gluteal Region and Posterior Thigh
Gene L. Colborn, David B. Lause in Musculoskeletal Anatomy, 2009
The obturator internus muscle arises within the pelvis from the internal surface of the hip bone and the obturator membrane, inferior to the true pelvic brim. From a somewhat triangularly-shaped field of origin, its muscle fibers converge to form a shiny white tendon which leaves the pelvis through the lesser sciatic foramen. The superior and inferior gemelli arise from the margins of the lesser sciatic foramen, above and below the emerging obturator internus tendon. The three muscles combine as a tripartite muscle/tendon unit (referred to clinically as the “obturator-gemelli complex”) which inserts upon the medial aspect of the greater trochanter. These muscles act syngergistically with other short lateral rotators of the hip joint.
Biofeedback Treatment for Functional Anorectal Disorders
Laurence R. Sands, Dana R. Sands in Ambulatory Colorectal Surgery, 2008
The Beyond Kegels, a complete rehabilitation program for pelvic muscle dysfunction developed by Hulme, is based on the principal that the support system for the pelvic organs includes more than just the PFMs. This support system, referred to as the pelvic rotator cuff (PRC), includes the obturator internus, the pelvic diaphragm (levator ani), the urogenital diaphragm, and adductor muscles. In summary, these muscles function as an interdigitated and interrelated synergistic unit, rather than separate entities, to support abdominal organs, stabilize the lumbopelvic and sacroiliac region, and reflexively act for continence. Thus, as the obturator internus muscle contracts, it acts as a pulley, lifting the pelvic diaphragm and facilitating closure of the urogenital diaphragm. As the adductor contracts, it lifts the pelvic diaphragm through overflow (proprioceptive neuromuscular facilitation) principles via the close approximation of their attachments on the symphysis pubis. The balance and work/rest cycle of the obturator and adductor muscles function as an integral part of the urogenital continence system to maintain bladder and bowel continence and to facilitate effective and efficient elimination.
Dynamic Anatomy of the Pelvic Floor
Victor Gomel, Bruno van Herendael in Female Genital Prolapse and Urinary Incontinence, 2007
Muscles: The Pubococcygeus and the Puborectalis muscles, in the middle compartment, are part of the levator ani muscular complex. The pubococcygeus runs from the Os Pubis towards the Os Coxys in the midline encircling the hiatus genitalis and attaches to the arcus tendineus musculi levator ani on the lateral side of the pelvis (Fig. 11). The deep transverse perineal muscle runs from side-to-side deep in the pelvis encircling the vagina. The superficial transverse perineal muscle runs from the side wall to the central tendon of the perineum just under the vagina. The obturator internus muscle covers the lateral and side aspect over the obturator membrane.
Ten-Step Surgical Approach to Management of Pathology of the Ischiorectal Fossa—A Review of the Literature and Application in a Rare Pelvic Schwannoma
Published in Journal of Investigative Surgery, 2022
Sarah Louise Smyth, Sunanda Dhar, Miss Lucy Cogswell, Hooman Soleymani majd
The transichiorectal approach provides direct access to Alcock’s canal with minimal pelvic muscle and ligament disruption [5, 7]. The procedure requires an in-depth knowledge of the pelvic anatomical spaces [4]. The pudendal nerve arises from the S2-4 sacral nerve and travels forward laterally in the pelvis within the obturator internus fascial sheath [8]. It has both motor and sensory functions. The ischiorectal fossa is a pyramidal space lateral to the anal canal and below the pelvic diaphragm with the apex at the anal canal and obturator fascia boundary, and the base at the perineal surface. It is bound medially by the levator ani, external anal sphincter and anal fascia, laterally by the ischial tuberosity and obturator internus muscle, anteriorly by the urogenital diaphragm fascia and Colles’ transverse perineal muscle fascia and posteriorly by the gluteus maximus and sacrotuberous ligament [2, 9]. It contains the internal pudendal, posterior labial and inferior rectal vessels and nerve, the perineal S4 branch, the perforating cutaneous nerve and lymphatic tissue [1, 3].
Diagnosis and treatment of pudendal and inferior cluneal nerve entrapment syndrome: a narrative review
Published in Acta Chirurgica Belgica, 2022
Katleen Jottard, Pierre Bonnet, Viviane Thill, Stephane Ploteau, Stefan de Wachter
The PN has been referred to as the king of the perineum [3]. Indeed, the PN plays a major role in the fecal and urinary continence mechanisms and is important for normal sexual functioning. The PN has both motor and sensory functions and carries sympathetic fibers. It arises from the second, third, and fourth sacral ventral rami at the inferior edge of the piriformis muscle [4]. Before entering the gluteal region, the nerve passes through the infrapiriformis foramen, which is a part of the greater sciatic foramen. The nerve then passes posterior from the ischial spine or sacrospinous ligament (SSL), medial to the internal pudendal vessels, to finally enter the perineum through the Alcock’s canal, a fold of the obturator internus muscle fascia. It continues to course through the pudendal canal (Alcock’s canal), giving off three consecutive branches on its path: the inferior rectal (anal) nerve and its branches, the perineal nerve and its branches and the dorsal nerve of the penis or clitoris.
An update on research and outcomes in surgical management of vaginal mesh complications
Published in Expert Review of Medical Devices, 2019
Dominic Lee, Philippe E. Zimmern
Intraoperative ultrasound can be utilized to assist in locating the MUS if identification during surgery proves difficult. This is especially so when a MUS placed long ago has embedded into the urethral wall or rolled on itself and displace proximally near the bladder neck and is not visible or palpable on the outer surface of the urethra. To minimize the risk of urethral injury, we start our sling localization laterally at the 3 or 9 o’clock position and divide the sling there. Identification of the sling at either of these locations appeared to minimize the risk of urethral injury. Surgical loops may be beneficial in the identification and dissection of the sling during its removal. Once the division of one side of the urethra is achieved, the sling can be carefully peeled off the under surface of the urethra from one side to the opposite side using diathermy on low current. We aim for maximal sub-urethral sling excision and the lateral extensions of the TOT mesh towards the obturator internus muscle or the retropubic tape extensions of the TVT is left intact since this has not been necessary in our experience. If the mesh was a mini-sling, we were able to completely remove the mesh in all cases [27]. Urethro-cystoscopy was repeated. If no urethral injury is visible, the urethral catheter is replaced, and the vaginal incision is closed, followed by a vaginal pack insertion for tamponade effect.
Related Knowledge Centers
- Ischium
- Lesser Sciatic Foramen
- Obturator Foramen
- Pelvic Brim
- Pelvic Cavity
- Hip Bone
- Pelvis
- Obturator Membrane
- Pubis
- Hip