Obturator nerve
The obturator nerve is a nerve of the lumbar plexus ( lumbar plexus ). In humans it has its origin in the 2nd to 4th lumbar segment of the spinal cord (L2 – L4), in domestic animals in the rear lumbar region (L4 – S1). It pulls inside the bony pelvis and then with the vena and arteria obturatoria through the canalis obturatorius to the inside of the thigh .
The obturator nerve motor innervates the adductors of the legs (in animals, the adductors of the hind limbs):
- Obturator externus muscle
- Adductor magnus muscle (together with tibial nerve )
- Adductor longus muscle
- Adductor brevis muscle
- Pectineus muscle (together with femoral nerve )
- Gracilis muscle
The nerve also sensitively innervates the hip joint , as well as a small area of skin on the inside of the thigh in humans.
Obturator paralysis
Paralysis of the obturator nerve occurs primarily during childbirth. As the newborn baby passes through the pelvis, it can pinch the nerve against the inner pelvic wall. This is particularly common in cattle , as cows have a relatively narrow birth canal. Paralysis rarely occurs after surgical removal of the lymph nodes in prostate cancer , as this can also damage the nerve.
In the case of such paralysis, the leg is slightly abducted and can even slide completely to the side on a smooth surface. When moving forward, it is not guided in a straight line, but in an outward arc.
Obturator blockade
The obturator nerve blockade is performed in urological interventions on the bladder when tissue on the side wall of the bladder is to be removed by means of electrocautery through the urethra (transurethral) . The obturator nerve runs immediately outside the bladder wall and could be irritated by the application of current to the bladder, which would result in reflex contractions of the adductor muscles on the leg, which would allow the bladder to be perforated by the resectoscope inserted there. The nerve block is designed to prevent these contractions.
Further indications are the addition of an incomplete “ 3-in-1 block ”, pain syndromes in the hip joint (sensitive branches of the anterior ramus) and adductor spasm conditions, in which a pain catheter can also be inserted for continuous pain therapy.
literature
- Franz-Viktor Salomon: nervous system, systema nervosum. In: Franz-Viktor Salomon, Hans Geyer, Uwe Gille (Ed.): Anatomy for veterinary medicine. Enke, Stuttgart 2004, ISBN 3-8304-1007-7 , pp. 464-577.
- Michael Schünke , Erik Schulte , Udo Schumacher : Prometheus. Anatomy Learning Atlas. General anatomy and motor system. 2nd revised and expanded edition. Thieme, Stuttgart et al. 2007, ISBN 978-3-13-139522-1 , p. 528.