Obturator Canal

canalis obturatorius

The obturator canal is a 2-3 cm fibro-osseous tunnel in the superolateral corner of the obturator foramen, through which the obturator nerve, artery, and vein pass from the pelvis into the medial thigh. It is bounded superiorly by the obturator groove of the pubic bone and inferiorly by the obturator membrane and obturator internus muscle.

Region: Thigh

Clinical Relevance

Clinical Notes

The obturator canal is the site of obturator hernia (most common in thin elderly women), which presents with medial thigh pain (Howship-Romberg sign — medial thigh pain with hip extension, adduction, and medial rotation from nerve compression). Obturator nerve entrapment within the canal produces medial thigh pain and weakness of hip adduction in runners and cyclists. Laparoscopic repair of obturator hernias requires knowledge of the canal boundaries.

Pathology

Common Injuries & Conditions

Obturator Hernia

Peritoneal protrusion through the obturator canal producing the Howship-Romberg sign (medial thigh pain with hip extension), most common in thin elderly women and often diagnosed at emergency surgery for small bowel obstruction.

Obturator Nerve Entrapment

Compression of the obturator nerve within the obturator canal producing medial thigh pain and adductor weakness in endurance athletes, confirmed by MRI or diagnostic nerve block.