Abstract:
PURPOSE : Several surgical and clinical procedures are performed in the area of the medial compartment of the
thigh. This places the obturator nerve and its branches in potential danger of injury. This study aimed to provide
a clear description of the anatomy and course of the obturator nerve and its branches. METHODS : One hundred and
one formalin-fixed cadavers were dissected just lateral to the lumbar vertebra to describe the origin and course of
the obturator nerve, as well as its relation to other anatomical structures. The location of the obturator nerve
within the obturator foramen was quantified by measuring the distance from three bony landmarks of the
obturator foramen to the nerve. FINDINGS : In 20% of cases the obturator nerve originated from L3 and L4 rather
than L2 to L4 in the combined sample. The bifurcation of the nerve occurred intrapelvically in 2% of cases,
within the obturator canal in 93% of cases and extrapelvically in 5% of the sample. Regarding the course in the
abdomen, the L3 root joined the L4 root more distally after exiting the psoas major muscle. In all cases on the left
(n = 97) and 99% on the right, the anterior branch innervated the muscles of the medial thigh, in one case on the
right the anterior branch innervated the pectineus muscle. The posterior branch assisted the anterior branch in
the innervation adductor brevis in 10% on the left and 11% on the right sides.
CONCLUSION : The results of this study may be used in the pre-operative preparation of surgeons that are to perform
surgery in the area of the obturator foramen such as obturator nerve blocks for pain relief of adductor muscle
contractions, prevention of adduction of the thigh during transurethral bladder surgery, additional analgesia
after knee surgery, chronic hip pain, as well as postoperative analgesia after hamstring harvest for anterior
cruciate ligament reconstruction.
