- Anatomy:
- formed from anterior branches of
L2,
L3,
L4 (see
innervation of muscles of the lower limb)
- largest nerve formed from anterior divisons of
lumbar plexus ;
- roots unite within the posterior part of psoas, & then descends thru psoas & runs downward over sacral ala into lesser pelvis, lying
lateral to ureter & internal iliac vessels;
- enters the upper part of the obturator foramen and then subsequently divides into anterior and posterior branches;
- Anterior Branch:
- runs in front of obturator externus &
adductor brevis ;
- it runs behind the
pectineus and
adductor longus muscles;
- gives off articular twig that enters hip joint thru acetabular notch;
- supplies muscular branches to hip
adductors & then divides into cutaneous, vascular, and communicating vessels;
- Cutaneous Branch:
- when present, it assists in innervation of skin and fascia over distal 2/3 of thigh;
- Posterior Branch:
- pierces anterior part of obturator externus;
- nerve then runs downward behind the
adductor brevis & and in front of the
adductor magnus;
- it then splits into branches that are distributed to upper (adductor) part of
adductor magnus & sometimes to
adductor brevis;
Obturator-nerve palsy resulting from intrapelvic extrusion of cement during total hip replacement. Report of four cases.
