Entrapment of the obturator nerve is a little recognized and rarely taught cause of pelvic and grointhighknee pain. The nerve path continues by following along the lateral wall of the pelvis, passing through the obturator canal, to enter the medial compartment of the thigh. Zager case presentation a 65yearold female underwent total abdominal hysterectomy with bilateral salpingooophorectomy tahbso for endometrial cancer. The obturator nerve divides into anterior and posterior branches. You may not embed one of our images on your web page without a link back to our site. The obturator nerve can be blocked with the other nerves of the lumbar plexus using the psoas compartment approach. It arises from the ventral divisions of the fifth lumbar and first and second sacral nerves. Historically, obturator nerve block onb has been considered a technically challenging procedure. Clinically relevant anatomy the obturator nerve is derived from l24 and travels along the medial border of the psoas muscle. The obturator nerve is the second major nerve that arises from l2, l3 and l4 ventral rami of the lumbar. Connection between pelvic pain and obturator internus muscle. The obturator nerve arises from the anterior division of l2l4 ventral rami. It originates from the inferior pubic rami and inserts on the posterior surface of the linea aspera.
During a routine gross anatomy dissection class for undergraduate students at the all india institute of medical sciences. The obturator nerve arises from the lumbar plexus and provides sensory and. Both the anterior and posterior branches of the nerve may pass posterior to adductor brevis. Preventing the obturator nerve reflex full text view. The nerve descends medial to psoas major to the obturator canal where it divides into anterior and posterior divisions. The obturator nerve is clinically relevant in certain pathologic conditions and.
Ultrasoundguided onb techniques and unresolved issues regarding these procedures are also discussed. Instant anatomy lower limb nerves obturator instant anatomy lower limb. Obturator nerve block atlas of pain medicine procedures. It travels through the obturator foramen with the obturator artery and vein into the thigh. Nerve innervations are done by the obturator nerve l2l4. The anterior division exits from the obturator canal to. The obturator nerve forms in the lumbar plexus from the anterior primary rami of l2l4 roots and descends to the pelvis in the psoas muscle. Obturator externus muscle radiology reference article. Textbook of medicine hand therapy, massage therapy, nbcot exam prep. The obturator nerve innervates a portion of the hip joint, most of the adductor muscles, a variable portion of the medial aspect of the femur, and has variable skin distribution on the medial aspect of the thigh. Peripheral blockade of the obturator nerve can be combined with either general or spinal anesthesia. The obturator nerve is a rare site of schwannoma, although cases of retroperitoneal schwannoma have been described. Nerve to the obturator internus and superior gemellus a branch of the sacral plexus l5, s1 l5, s1 arterial supply internal pudendal and superior and inferior gluteal arteries. Anatomy lower limb book study guide by ayanavee includes 140 questions covering vocabulary, terms and more.
A motor nerve originating in the lumbar plexus and composed of axons from spinal cord segments l2l4. It courses medial to the psoas major muscle, along the sidewall of the pelvis, with the internal iliac vessels. Apr 07, 2015 the obturator nerve begins at the medial border of the psoas major muscle. However, the pudendal nerve can sometimes get trapped in the obturator fascia, leading to many types of pelvic issues such as neuralgia or severe pelvic pain. The obturator nerve may have additional roots from the first or fifth lumbar nerves.
Mar 08, 2012 motor blockade of the obturator nerve will prevent this adduction in the event of inadvertent nerve stimulation. Adductor brevis muscle an overview sciencedirect topics. The gracilis is a spiral unipennate muscle in the medial thigh compartment, which is innervated by the anterior branch of the obturator nerve and receives its vascular supply from the medial circumflex femoral artery, superficial femoral artery, deep femoral artery, descending genicular artery, and the anterior branch of the obturator artery. Instant anatomy upper limb nerves skin specific brachial. The obturator nerve is a major peripheral nerve of the lower limb. The obturator nerve in human anatomy arises from the ventral divisions of the second, third, and fourth lumbar nerves in the lumbar plexus. The sciatic nerve is the major nerve arising from the lumbosacral plexus. It passes into the thigh through the obturator foramen of the pelvic bones and innervates the adductor longus, adductor brevis, gracilis, pectineus, obturator externus, and adductor magnus muscles. A band running from the pubic tubercle to the anterior superior iliac spine. Near the obturator foramen the nerve gives off an articular branch to the hipjoint. Obturator nerve anatomy everything you need to know dr. Entrapment of the obturator nerve is an underrecognized and rarely taught cause of groin, thigh, and knee pain. It travels through the obturator foramen an opening in the pelvic bone before entering the thigh, where it branches. The anterior divisions of the lumbar nerves, sacral nerves, and coccygeal nerve form this plexus, the first lumbar nerve being frequently joined by a branch from the twelfth thoracic nerve inguinal ligament.
The sciatic nerve leaves the pelvis through the greater sciatic foramen sciatic notch passing below the piriformis muscle and over the obturator internus muscle fig. The obturator membrane is covered on either side by the obturator muscles. Obturator paralysis in cattle musculoskeletal system. It subsequently then divides upon exiting the canal into an anterior and posterior division. Mar 18, 2020 the classic description of the anatomic course of the obturator nerve comes from grays anatomy. Assembly of steel spindle, mushroom head, obturator rings, and a gascheck or obturator pad of tough plastic material used as a seal to prevent the escape of propellant gases around the breechblock of guns using separateloading ammunition, and therefore not having the obturation provided by a cartridge case.
The obturator nerve is formed by the anterior divisions of the second, third and fourth lumbar nerves. This practical guide presents the principles and techniques of ultrasound guided blocks in 11 chapters which include blockade of the femoral nerve, saphenous nerve adductor canal, lateral femoral cutaneous nerve, obturator nerve, sciatic nerve in the gluteal, subgluteal, proximal thigh and popliteal regions, and ankle. Despite initial claims, a perivascular inguinal block winnies 3in1 block only rarely reaches the obturator nerve, as demonstrated by macalou et al. Ideal for use alongside a core anatomy textbook, instant anatomy is the. Its fibers originate from the l4 to s3 spinal roots. How do i selftreat sit bone pain and obturator internus. Obturator article about obturator by the free dictionary. Accessory obturator nerve wikimili, the free encyclopedia. In human anatomy, the accessory obturator nerve is an accessory nerve in the lumbar region present in about 29% of cases. The obturator fascia forms a canal called alcocks canal, which encloses the pudendal vessels and the pudendal nerve, and cross the obturator internus muscle.
Instant anatomy lower limb nerves obturator instant anatomy is a specialised web site for you to learn all about human anatomy of the body with diagrams, podcasts and revision questions. The nerve to obturator internus is a nerve that innervates the obturator internus and gemellus superior muscles. The obturator nerve should not be confused with the nerve to obturator internus. Variation in the obturator vasculature during routine. Variation in the obturator vasculature during routine anatomy.
We also checked their obturator internus and externus, but what we found, in their case, and im kind of leaning this way for your description as well, is gluteus minimus, and especially the trigger points from gluteus minimus which refer towards the sit bone and close to the center line, even near the sacrum there. There is considerable risk that the adductor muscles will be damaged and that permanent recumbency will result. Internal surface of obturator membrane and posterior bony margins of obturator foramen insertion. Instant anatomy upper limb nerves skin specific brachial plexus instant.
Aug 19, 2016 the obturator artery normally originates from the internal iliac artery while the obturator vein drains into the internal iliac vein. I actually recently worked with somebody who has kind of sit bone pain going on. Instant anatomy is a specialised web site for you to learn all about human anatomy of the body with diagrams, podcasts and revision questions. Nerves, blood vessels and lymph advanced anatomy 2nd. Symptoms include medial thigh or groin pain, weakness with leg adduction, and sensory loss in the medial thigh of the. Gross anatomy course pelvis the nerve descends medi. The nerve is also responsible for the motor innervation of the adductor muscles of the lower limb external obturator. Nerve to internal obturator and superior gemellus radiology. Instructions instant anatomy pages 1 16 text version. Wileyblackwell 2010 sciatic nerve this nerve may divide into its two components anywhere from the pelvis to the popliteal fossa short head biceps femoris tibial nerve common fibular nerve adductor magnus medial collateral ligament semi membranosus.
After forming in the psoas muscle, it travels anterior to the sacroiliac joint. Recent evidence support that this nerve arises from dorsal divisions. The obturator nerve is responsible for the sensory innervation of the skin of the medial aspect of the thigh. It exits the pelvis through the obturator canal in the upper part of the obturator foramen, where it divides into anterior and posterior divisions. The major contribution to the obturator nerve is from l3 and the least contribution is usually from l2. Because the adductors are innervated by the obturator nerve, an animal adopts a basewide stance or, in recumbency, a sitting position with both hindlimbs extended forward. The posterior branch of the obturator nerve pierces the anterior part of the obturator externus, and supplies this muscle. During a routine gross anatomy dissection class for undergraduate students at the all india institute of medical sciences, new delhi, india, in 2016, a rare unilateral variation in the obturator vasculature was found in a female cadaver of approximately 55 years. The obturator nerve originates from l24 and is the only motor nerve of the lumbar plexus to pass through the pelvis without innervating any pelvic structures. The nerve supplies the obturator internus and superior gemellus muscles as well as the fascia of the lateral side wall of the ischioanal fossa. Obturator neuropathy is caused by compression of the obturator nerve. Obturator nerve medical definition merriamwebster medical.
It arises from the anterior divisions of l24 in the lumbar plexus gross anatomy course pelvis. An accessory obturator nerve has a reported incidence of 29%, %, or 8% according to different authors. In most individuals, the nerve divides into an anterior branch and posterior branch before exiting the pelvis through the obturator foramen. The obturator nerve is the most cranial of the neurovascular bundle passing through the canal.
A nerve plexus is a plexus branching network of intersecting nerves. Obturator nerve definition of obturator nerve by the free. The obturator nerve arises from the lumbar plexus on the posterior abdominal wall and descends within the psoas muscle, emerging from the medial margin of the muscle to enter the pelvis. It is of small size, and arises from the ventral divisions of the third and fourth lumbar nerves. Types of activities reading physiopedia pages, journal articles, book chapters. Instant anatomy nerves lower limb, nerve, anatomy coloring book. The obturator artery normally originates from the internal iliac artery while the obturator vein drains into the internal iliac vein. In the pelvis, the obturator nerve can mimic pudendal neuralgia, hip pathology. The posterior branch of the obturator nerve lies within the fascia between the adductor brevis and adductor magnus muscles closed triangles. Quizlet flashcards, activities and games help you improve your grades.
The anterior branch of the obturator nerve is located at the hyperechoic thick fascia between the adductor brevis muscle and the pectineus arrows or adductor longus open triangles muscles. Medial surface of greater trochanter of femur, in common with superior and inferior gemelli action. Its anatomy is very important for operating on hernia patients. Vertebrae, femoral, common peroneal, deep peroneal, obturator nerve. Adductor brevis is a short muscle, lying inferior to adductor longus. Obturator nerve dysfunction can mimic hip pathology, groin strain, and claudication. In this article, we shall look at the anatomy of the obturator nerve its anatomical course, functions and clinical correlations. Obturator nerve easy learn world of anatomy youtube. The fibers of obturator nerve arise from ventral divisions of 2 nd, 3 rd and 4 th lumbar nerves. General patterns segmental muscle supply segmental movement supply skin cutaneous supply general skin. The obturator nerve is a large nerve arising from the lumbar plexus and the nerve of the medial compartment of the thigh. The presenting symptom is groin and medial thigh pain along with numbness in the medial thigh. It arises from the anterior divisions of l24 in the lumbar plexus.
It is a large nerve, which descends vertically within the psoas major muscle, before emerging from the inner border of the muscle in the abdomen. Feb 25, 2014 instant anatomy leg nerves cutaneous supply general. It descends through the fibers of the psoas major muscle and emerges from its medial border, running posteriorly to the common iliac arteries and laterally along the pelvic wall to the obturator. If you would like a large, unwatermarked image for your web page or blog, please purchase the appropriate license. The obturator nerve is a mixed nerve with motor and sensory fibers. The obturator nerve is derived from l24 and travels along the medial border of the psoas muscle. It then follows the wall of the lateral pelvis and passes through a fibroosseus canal that is formed by the internal and external obturator muscles and their fascia and the obturator sulcus of the pubic bone.
Ebraheims educational animated video describes the anatomy of the obturator nerve. The anatomy and function of the obturator nerve have been well studied, and are known to be occasionally damaged during extensive pelvic surgery, which most noticeably causes impairment of ipsilateral leg adduction. Sep 8, 2017 instant anatomy lower limb nerves cutaneous supply general. The nerve goes down in psoas major and issues from its medial border at the ala of the sacrum. Correction of iatrogenic injury of the obturator nerve. The nerve to obturator internus originates in the sacral plexus. Facial nerve cnvii vestibulocochlear nerve cnviii glossopharyngeal nerve cnix vagus nerve cnx accessory nerve cnxi hypoglossal nerve cnxii pathways. Obturator internus muscle an overview sciencedirect topics. Anatomy of obturator externus anatomy of obturator externus the obturator externus is one of the six short external rotators of the hip origin. One possible cause of pain is due to fascial entrapment of the nerve.
The obturator nerve is formed from the l24 nerve roots. Obturator mononeuropathy caused by pelvic cancers bladder carcinoma of unknown origin, lymphoma has been reported. The literature also includes cases of schwannoma involving the obturator nerve together with the femoral nerve. The obturator nerve arises from the second, third and fourth lumbar nerves. Behind the pectineus, it distributes branches to the adductor longus and gracilis, and usually to the adductor brevis, and in rare cases to the pectineus. Nerve innervations are by the obturator nerve l2l4. I started using this book when we started the head and neck section in my anatomy class and i was hooked. Course substance of psoas the obturator decends through the substance of the psoas and exits medially near pelvic brim. Jun 11, 2008 obturator neuropathy is a difficult clinical problem to evaluate. It shows structures such as nerves and blood vessels in their entirety, unlike the partial.
Obturator nerve definition of obturator nerve by medical. The obturator artery is a branch of the internal iliac artery that passes anteroinferiorly forwards and downwards on the lateral wall of the pelvis, to the upper part of the obturator foramen, and, escaping from the pelvic cavity through the obturator canal, it divides into both an anterior and a posterior branch. Obturator nerve entrapment genitofemoral nerve entrapment ilioinguinal. It shows structuressuch as nerves and blood vessels in their entirety, unlike the partial. The branch from the main trunk of the nerve to obturator externus may pass to the lateral instead of medial side of the obturator nerve. It arises from the third or more commonly the third and fourth lumbar nerves between the roots of the femoral and obturator nerves. Anatomy, bony pelvis and lower limb, thigh gracilis muscle. These videos are for educational purpose only for the medical students like mbbs, bds, bpt, nursing an. An accessory obturator nerve supplies the pectineus muscle of the thigh and is sensory to the hip joint. The nerve path continues by following along the lateral wall of the pelvis, passing through the obturator. An onb is performed to prevent thigh adductor jerk during transurethral resection of bladder tumor, provide analgesia for knee surgery, treat hip pain, and improve persistent hip. Nerve to the obturator internus and superior gemellus a branch of the sacral plexus l5, s1.
The obturator nerve arises from the lumbar plexus on the posterior abdominal wall and descends within the psoas. This book is distributed under the terms of the creative commons. Instant anatomy upper l imb nerves skin specific brachial plexus. Obturator nerve is a branch of the lumbar plexus that emerges from the medial border of the psoas muscle in the abdomen. In the pelvis, the obturator nerve can mimic pudendal neuralgia, hip pathology, groin strain, and claudication. The obturator canal is a passageway formed in the obturator foramen by part of. Anatomy the femoral nerve, formed by the dorsal divisions of the anterior rami of l2l4, is the largest terminal branch of the lumbar plexus. It arises from the anterior primary rami of l2, l3 and l4 in the lumbar plexus. Instant anatomy the book instant anatomy podcasts instant anatomy. Femoral triangle and gluteal region instant anatomy. Obturator nerve entrapment description femoral head.