N Obturatorius

N Obturatorius. The Obturator Nerve (n obturatorius) arises from the ventral divisions of the second third and fourth lumbar nerves the branch from the third is the largest while that from the second is often very small.

The obturator nerve in human anatomy arises from the ventral divisions of the second third and fourth lumbar nerves in the lumbar plexus the branch from the third is the largest while that from the second is often very small Latin nervus obturatoriusInnervates From L2L4To .

Variations of formation of n. femoralis, n. obturatorius and

FactsGeneral ConsiderationsUltrasound AnatomyDistribution of AnesthesiaEquipmentLandmarks and Patient PositioningGoalTechniqueIndications Relief of painful adductor muscle contractions to prevent adduction of the thigh during transurethral bladder surgery additional analgesia after major knee surgery and may provide pTransducer position medial aspect of the proximal thighGoal Local anesthetic spread in the interfascial plane in which the nerves lie or around the anterior and posterior branches of the obturator nerveLocal anesthetic 5 mL into each interfascial space or around the branches of the obturator nerve Ultrasound (US)guided obturator nerve block is simpler to perform and more reliable than surface landmark–based techniques There are two approaches to performing a USguided obturator nerve block The interfascial injection technique relies on injecting local anesthetic solution into the fascial planes that contain the branches of the obturator nerve With this technique it is not important to identify the branches of the obturator nerve on the sonogram but rather to identify the adductor muscles and the fascial boundaries within which the nerves lie This is similar in concept to other fascial plane blocks (eg the transversus abdominis plane[TAP] block in which local anesthetic solution is injected between the internal oblique and transverse abdominis muscles without the need to identify the nerves) Alternatively the branches of the obturator nerve can be visualized with US imaging and blocked after eliciting a motor response The obturator nerve forms in the lumbar plexus from the anterior primary rami of the L2–L4 roots and descends to the pelvis on the medial side of the psoas muscle In most individuals the nerve divides into an anterior branch and posterior branch before exiting the pelvis through the obturator foramen In the thigh at the level of the femoral crease the anterior branch is located between the fascia of the pectineus and adductor brevis muscles The anterior branch lies further caudad between the adductor longus and adductor brevis muscles The anterior branch provides motor fibers to the adductor longus brevis and gracilis muscles and cutaneous branches to the medial aspect of the thigh The anterior branch has great variability in the extent of sensory innervation of the medial thigh The posterior branch lies between the fascial planes of the adductor brevis and adductor magnus muscles (Figures 2 and 3) The posterior branch is primarily a motor nerve for the adductors of the Because there is great variability in the cutaneous innervation to the medial thigh demonstrated weakness of adductor muscle strength is the only reliable method of documenting a successful obturator nerve block (Figure 1) However the adductor muscles of the thigh may have coinnervation from the femoral nerve (pectineus) and the sciatic nerve (adductor magnus) Adductor motor strength is decreased by about 25% following femoral nerve blockade and 11% following sciatic nerve blockade For this reason complete loss of adductor muscle strength is uncommon despite a successful obturator nerve block The equipment recommended for an obturator nerve block includes the following 1 Ultrasound machine with linear (or curved) transducer (5–13 MHz) sterile sleeve and gel 2 Standard block tray 3 A 10mL syringe containing local anesthetic solution 4 A 10cm 21 to 22gauge shortbevel insulated needle 5 Peripheral nerve stimulator (optional) 6 Sterile gloves Learn more about Equipment for Peripheral Nerve Blocks With the patient supine the thigh is slightly abducted and laterally rotated The block can be performed either at the level of femoral (inguinal) crease medial to the femoral vein or 1–3 cm inferior to the inguinal crease on the medial aspect (adductor compartment) of the thigh (Figure 5) The goal of the interfascial injection technique for blocking the obturator nerve is to inject local anesthetic solution into the interfascial space between the pectineus and adductor brevis muscles to block the anterior branch and the adductor brevis and adductor magnus muscles to block the posterior branch When using US guidance with nerve stimulation the anterior and posterior branches of the obturator nerve are identified and stimulated to elicit a motor response prior to injecting local anesthetic solution around each branch The interfascial approach is performed at the level of the femoral crease With this technique it is important to identify the adductor muscles and the fascial planes in which the individual nerves are enveloped Color Doppler can be used to visualize the obturator arteries located near the nerve branches in order to avoid puncturing them although they are not always visible The US transducer is placed to visualize the femoral vessels The transducer is advanced medially along the crease to identify the adductor muscles and their fasciae The anterior branch is sandwiched between the pectineus and adductor brevis muscles whereas the posterior branch is located in the fascial plane between the adductor brevis and adductor magnus muscles The block needle is advanced to initially position the needle tip between the pectineus and adductor brevis (Figure 6a) At this point 5–10 mL of local anesthetic solution is injected The needle is advanced farther to position the needle tip be.

UltrasoundGuided Obturator Nerve Block NYSORA

The obturator nerve is one of the largest branches of the lumbar plexus t is a mixed nerve which arises from the ventral (anterior) rami of the spinal nerves L2 The function of the obturator nerve is to provide motor innervation to all the medial muscles of the thigh (hip adductors) except for the hamstring part of the adductor magnus.

Obturator nerve: Origin, course and function Kenhub

N obturatorius most frequently emerged from ventral branches of final lumbal nerves in pigs with six and seven lumbal vertebrae in 6666% of animals and somewhat more often in pigs with seven.