Obturator Nerve

- 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.

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, December 6, 2011 10:37 am