Redefining the coccygeal plexus

Abstract

The coccygeal plexus is variably described in anatomy texts and has rarely been studied despite the idiopathic nature of coccydynia in up to one-third of affected patients. The plexus was therefore investigated using a combination of microdissection and histology. The distal sacrum and coccyx in continuity with ischiococcygeus were removed en bloc from 16 embalmed cadavers (mean age 78 ± 10 years, 7 females) with no local disease. Ten specimens underwent microdissection of the coccygeal plexus and the remaining six were examined histologically after staining with hematoxylin and eosin and S100 immunohistochemistry to demonstrate nerve fibers. The coccygeal plexus is formed within ischiococcygeus from the ventral rami of S4, S5, and Co1 with a contribution (gray rami communicantes) from the sacral sympathetic trunk. It gives rise to anococcygeal nerves which pierce ischiococcygeus and the sacrospinous ligament to supply the subcutaneous tissue on the dorsal aspect of the coccyx. Some branches from the plexus pass medially anterior to the coccyx. The coccycgeal plexus is formed within ischiococcygeus rather than on its pelvic surface and appears to supply skin in the anococcygeal region. It probably also contributes to the innervation of ischiococcygeus, the sacrospinous ligament, coccygeal ligaments, and periosteum. It deserves to be considered as a potential pain generator that may be implicated in some patients with coccydynia.

The Efficacy of Extracorporeal Shock Wave Therapy for Chronic Coccydynia

“…It is associated with the fifth sacral and coccygeal nerve roots and the terminal sympathetic plexus. Coccydynia is defined as pain in the coccyx and/or coccygeal joints [1-5]; it is five times more common in women than in men [6]. Pain related to coccydynia is aggravated by sitting or prolonged sitting in the same position and cycling [1, 3, 7].…”

Novel approach for pericapsular radiofrequency ablation of sacrococcygeal junction for patients with coccydynia

“…It was originally described by Ricardo Plancarte in 1990 for the treatment of perianal cancer pain of visceral origin 6. Woon and colleagues reviewed the innervation of the coccygeal area and performed their own dissection which showed that the innervation of the coccyx is composed mostly of the coccygeal nerves and the lower sacral spinal nerves, which originate from the lower sacral nerve roots 7 10. The coccygeal plexus primarily innervates the anterior part of the coccyx.…”

“…It originates from the ventral rami of the sacral nerves S4 and S5 and the coccygeal nerves (figure 1). 11 The coccygeal plexus supplies the sacrospinous and coccygeal ligaments, soft tissue and skin overlying the ventral coccyx, external anal sphincter, coccygeal periosteum, sacrococcygeal joint, and anterior musculature including the ischiococcygeus, pubococcygeus, coccygeus and part of the levator ani 7 10 11. Despite a large number of coccygeal nerves are present in human embryos (up to a total of five), all but the first pair regress during embryo development 12.…”

“…An update understanding of the innervation of the sacrococcygeal and intercoccygeal joints revealed that these structures are innervated by coccygeal plexus, which is formed by the ventral rami of S4, S5 and first coccygeal nerve or Co1 (figure 1). 7 In addition to the sacrococcygeal and intercoccygeal joints, this coccygeal plexus also innervates the levator ani, external anal sphincter, and the skin between the anus and coccyx. The course of this plexus is complex but to selectively interrupt the innervation to the sacrococcygeal and intercoccygeal joints, a pericapsular approach can be used similar to the local infiltration analgesia strategy to other joints.…”

Spinal Cord Stimulation of the Sacral Region as a Treatment for Intractable Coccygodynia: A Case Study

“…The anococcygeal nerves originate from this plexus and function to supply the skin adjacent to the sacrotuberous ligament on the dorsal aspect of the coccyx (16,17). The coccygeal plexus has been theorized to play a role in generating the pain seen in coccygodynia, therefore making it an ideal site for neuromodulation (18).…”