Pudendal Nerve Entrapment
Pen and Ink and Zbrush

Pudendal Nerve Entrapment:
An Anatomical Study And Three-Dimensional
Visualization Of Nerve Variations And Branching Patterns

Pudendal nerve entrapment can lead to chronic, debilitating pain.  The complex course and anatomical variations of the pudendal nerve and its branches provide opportunities for injury and entrapment. Originating from the sacral plexus, the pudendal nerve leaves the pelvis through the greater sciatic notch and travels between the sacrospinous ligament and sacrotuberous ligament, into the ischiorectal fossa where it enters Alcock’s canal and exits anteriorly traveling through the pubic ramus canal as the dorsal nerve of the clitoris or the penis.  The rectal and perineal nerve branches arise at varying sites along this pathway.

Cadaveric dissections of 10 hemipelvises were completed to study the multiple branching patterns and varied course of the pudendal nerve.  A detailed Illustration and diagrammatic insert documenting measurements was created of each hemipelvis.  CT scans and High density MR Neurography were taken of one male and one female pelvis block pre and post surgical dissection in which pudendal nerve branches were identified and marked.  A 3D computer model showing the most common branching pattern and pathway variations of the pudendal nerve seen in the above research was created using Zbrush.

The culmination of the research was a this two minute animation to educate physicians and patients about pudendal nerve entrapment and the anatomical variations of the pudendal nerve.

This research will enable physicians surgeons, radiologists to better visualize the course of the pudendal nerve, its variations, and the zones of entrapment, thus aiding in better understanding of pudendal nerve anatomy and its role in chronic pelvic pain.

Below is an example of the layout created for each of the 10 hemipelvis dissections. Layout includes a pen & ink illustration, diagrammatic insert showing branching pattern and recorded measurements and text explaining observations.

Hemipelvis 1