Accessory obturator nerve

The accessory obturator nerve is a nerve in the human body that is present in approximately 10% of the population. It is considered an anatomical variant and is part of the lumbar plexus.

Anatomy

The accessory obturator nerve arises from the ventral divisions of the third and fourth lumbar nerves (L3 and L4). It is a branch of the lumbar plexus, which is a network of nerves in the lower back that supplies the lower limb.

The nerve descends along the medial border of the psoas major muscle, and it passes over the superior pubic ramus. It then enters the thigh, where it supplies the pectineus muscle.

Function

The primary function of the accessory obturator nerve is to innervate the pectineus muscle, which is involved in hip flexion and adduction. In some cases, it may also provide sensory innervation to the hip joint and the medial thigh.

Clinical significance

The presence of the accessory obturator nerve can have clinical implications, particularly in surgical procedures involving the pelvis or hip joint. Surgeons must be aware of its possible presence to avoid inadvertent injury during operations such as hip replacement surgery.

In cases where the accessory obturator nerve is present, it may contribute to the innervation of the hip joint, and its injury could lead to sensory deficits or weakness in the medial thigh.

Related pages

• Lumbar plexus
• Obturator nerve
• Pectineus muscle
• Hip joint

Gallery

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  Diagram of the lumbar plexus with the accessory obturator nerve.
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  The accessory obturator nerve in relation to the psoas major muscle.