Revisiting the Middle Cluneal Nerves: An Anatomic Study with Application to Pain Syndromes and Invasive Procedures Around the Sacrum.

World Neurosurg. 2019 Jul;127:e1228-e1231. doi: 10.1016/j.wneu.2019.04.109. Epub 2019 Apr 19.

Kikuta SIwanaga JWatanabe KTubbs RS.


Abstract

OBJECTIVE:

The middle cluneal nerves (MCNs) are stated to arise from the sacral dorsal rami of S1 to S3 and supply the gluteal skin, but their detailed anatomy is unclear and often variably depicted and described. Therefore, the goal of this study was to revisit the anatomy of the MCNs and provide a clearer picture of their morphology.

METHODS:

Five fresh-frozen Caucasian cadavers (10 sides) (2 men and 3 women) were dissected for this study. The sacral dorsal rami from each posterior sacral foramen were identified and traced laterally to identify the MCNs. The contribution, pathway, and distribution of the MCNs were investigated.

RESULTS:

Each sacral dorsal ramus joined to form the posterior sacrococcygeal plexus. A total of 25 MCNs were identified. The MCNs were formed by the sacral dorsal rami of S1-2 in 48% (12/25), S1-3 in 4% (1/25), S1-4 in 20% (5/25), S2-3 in 8% (2/25), and S2-4 in 20% (5/25). The MCNs pierced the gluteus maximus by 2 different pathways and supplied the gluteal skin or the gluteus maximus muscle.

CONCLUSIONS:

We clarified the anatomy and variations of the MCNs and revisited its current nomenclature. Such knowledge might improve diagnoses and invasive procedure outcomes in patients with pathology in the region of the MCNs.

Copyright © 2019 Elsevier Inc. All rights reserved.

KEYWORDS:

Anatomy; Cadaver; Middle cluneal nerve; Posterior sacrococcygeal plexus; Sacral dorsal rami