Inferior gluteal and other nerves associated with sacrospinous ligament: a cadaver study

• Published in: American journal of obstetrics and gynecology 2016-11, Vol.215 (5), p.646.e1-646.e6
• Main Authors: Florian-Rodriguez, Maria E., MD, Hare, Adam, MD, Chin, Kathryn, BS, Phelan, John N., PhD, Ripperda, Christopher M., MD, Corton, Marlene M., MD, MSCS
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Buttocks - anatomy & histology; Buttocks - innervation; Female; gluteal pain; Gynecologic Surgical Procedures; Humans; inferior gluteal nerve; injury; Ligaments - anatomy & histology; Ligaments - surgery; Lumbosacral Plexus - anatomy & histology; Lumbosacral Plexus - injuries; Middle Aged; Obstetrics and Gynecology; Pain, Postoperative - etiology; Pelvic Organ Prolapse - surgery; sacrospinous ligament; sacrospinous ligament fixation
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1016/j.ajog.2016.06.025

Background Reported rates of gluteal pain after sacrospinous ligament fixation range from 12–55% in the immediate postoperative period and from 4–15% 4–6 weeks postoperatively. The source of gluteal pain often is attributed to injury to the nerve to levator ani or pudendal nerve. The inferior gluteal nerve and other sacral nerve branches have not been examined thoroughly as potential sources of gluteal pain. Objectives The purpose of this study was to further characterize anatomy of the inferior gluteal nerve and other nerves that are associated with the sacrospinous ligament from a combined gluteal and pelvic approach and to correlate findings to sacrospinous ligament fixation. Study Design Dissections were performed in female cadavers that had not been embalmed with gluteal and pelvic approaches. From a pelvic perspective, the closest structure to the superior border of the sacrospinous ligament midpoint was noted, and the sacral nerves that perforated the ventral surface of coccygeus muscle were examined. From a gluteal perspective, the closest distances from ischial spine to the pudendal, inferior gluteal, posterior femoral cutaneous, and sciatic nerves were measured. In addition, the closest distance from the midpoint of sacrospinous ligament to the inferior gluteal nerve and the origin of this nerve were documented. The thickness and height of the sacrospinous ligament at its midpoint were measured. Sacral nerve branches that coursed between the sacrospinous and sacrotuberous ligaments were assessed from both a pelvic and a gluteal approach. Descriptive statistics were used for data analysis. Results Fourteen cadavers were examined. From a pelvic perspective, the closest structure to the superior border of sacrospinous ligament at its midpoint was the S3 nerve (median distance, 3 mm; range, 0–11 mm). Branches from S3 and/or S4 perforated the ventral surface of coccygeus muscles in 94% specimens. From a gluteal perspective, the closest structure to ischial spine was the pudendal nerve (median distance, 0 mm; range, 0–9 mm). Median closest distance from inferior gluteal nerve to ischial spine and to the midpoint of sacrospinous ligament was 28.5 mm (range, 6–53 mm) and 31.5 mm (range, 10–47 mm), respectively. The inferior gluteal nerve arose from dorsal surface of combined lumbosacral trunk and S1 nerves in all specimens; a contribution from S2 was noted in 46% of hemipelvises. At its midpoint, the sacrospinous ligament median thickness was 5 mm (range