Two layers of fascia envelop the pudendal nerve canal: a cadaver study

This study aimed to examine the pudendal nerve in the context of tumors involving the pudendal canal and to clarify its anatomical course and the structural composition of Alcock's canal, while elucidating the relationships among the obturator internus nerve, sacrotuberous ligament, and fascia of the obturator internus muscle.

Six cadavers (12 pelvic halves) were dissected. The dissections focused on the pudendal canal, particularly the positions and interrelationships of the fasciae, muscles, ligaments, and surrounding fascial structures from medial and posterior perspectives.

The sacrotuberous ligament comprised two distinct layers, with the pudendal canal located within its structure. The proper fascia was distinguishable and situated on the muscle side of the obturator internus muscle. The pudendal nerve was traced within the fascia of the sacrotuberous ligament, whereas the obturator internus nerve coursed between the obturator internus muscle and its proper fascia. Coronal section examination of the right pelvis confirmed that the pudendal nerve was enveloped by fascia. The obturator internus nerve ran along the muscle side of the obturator internus fascia, occupying a layer distinct from that of the pudendal nerve.

The pudendal nerve travels within the fascia derived from the sacrotuberous ligament and does not pass through the fascia of the obturator internus. The proper fascia of the obturator internus muscle is located relatively close to the muscle, and the obturator internus nerve courses between the obturator internus muscle and its own fascia. These findings describe the anatomy of the pudendal canal and may provide a foundation for future surgical investigation.