From: Phrenic Nerve Palsy and Regional Anesthesia for Shoulder Surgery:Anatomical, Physiologic, and Clinical Considerations Anesthes. 2017;127(1):173-191. doi:10.1097/ALN.0000000000001668 Figure Legend: Anterior (left) and posterior (right) innervation of the shoulder. (A) The distribution of cutaneous innervation of the shoulder. Common port-hole incisions (red crosses), including superior, anterior, lateral, and posterior incisions made for arthroscopic shoulder surgery and the deltopectoral incision (red line) for open shoulder surgery are represented. (B) The route taken by nerves to supply both skin and bone in the shoulder. (C) The osteotomal supply of the shoulder. (D) An index of color coding of dermatomes, nerves, and osteotomes. Images adapted with permission from Maria Fernanda Rojas Gomez and reproduced with permission from Ultrasound for Regional Anesthesia (USRA; http://www.usra.ca). Date of download: 10/4/2017 Copyright © 2017 American Society of Anesthesiologists. All rights reserved.