Surface Localization and Bony Landmarks of Posterior Sacral Foramina for Neuromodulation: A Cadaveric Study

Abstract

Introduction and Rationale:  Electrical stimulation of sacral nerve roots can affect neural reflex behaviour with respect to the lower urinary tract in patients with urinary symptoms which are refractory to conventional treatment. Electrical stimulation can be used for the management of pain, particularly perineal pain with selective stimulation of motor and or sensory nerves.

Objective: The aim of study was to determine surface anatomical landmarks of the sacrum to facilitate identification of posterior sacral foramina which will aid in successful stimulation of sacral spinal nerves for management of certain pelvic floor disorders like urinary and fecal incontinence.

Method: This study was conducted on 20 human cadavers and dissection was done. Different measurements were with help of digital vernier caliper and flexible measuring tape. The measurements made were horizontal and vertical diameter, Distance between the medial and lateral edges,Distance (vertical distance) between posterior sacral foramina on both sides and Distance between tip of coccyx and superior aspect of S3.

Results: Detailed knowledge of anatomy of posterior sacral foramina will help in electrode placement. Sacral nerve stimulation is common line of treatment for various pelvic floor disorders.