Anatomical and surgical considerations of the sacrotuberous ligament and its relevance in pudendal nerve entrapment syndrome

Abstract

In view of the paucity of literature, this study was undertaken to reappraise the gross anatomy of the sacrotuberous ligament (STL), with the objective of providing an accurate anatomical basis for clinical conditions involving the STL. We studied the gross anatomy of the STL in 50 formalin fixed cadavers (100 sides) during the period of 2004-2005. All specimens exhibited an STL with a ligamentous part and (87%) of specimens exhibited a membranous (falciform) segment, which extended towards the ischioanal fossa. The variations of the falciform extensions were classified into three types. In Type I (69%), the falciform process extended towards and along the ischial ramus to terminate at the obturator fascia. In Type II (108%), the falciform process extended along the ischial ramus, fused with the obturator fascia and continued towards the ischioanal fossa. In addition, the medial border of the falciform process descended to fuse with the anococcygeal ligament, forming a continuous membrane. Lastly, in Type III (13%), the falciform process of the STL was absent. The above mentioned data could have an important implication to the understanding of the relationship between the pudendal nerve and the sacrotuberous ligament and their relevance to pudendal nerve entrapment syndrome.

The course and branching pattern of pudendal nerve in fetus

“…The knowledge of the main trunk diameter and the nerve length in the pudendal canal is important in pudendal canal decompression surgery, which is applied for pudendal canal entrapment syndrome (Loukas et al, 2006); and pudendal nerve stimulation, which is successfully and extensively used to treat neurogenic and non-neurogenic bladders (Reitz et al, 2003). Because of the mentioned clinical importance, we measured the average length of the pudendal nerve trunks before the dorsal nerve of penis (clitoris) branch to be 7.35 6 3.50 mm and the average diameter of the main trunk of pudendal nerve in Type I-a and I-b groups to be 0.98 6 0.33 mm.…”

“…Detailed anatomical knowledge of pudendal nerve variation and its position and proximity to the piriformis muscle is of interest in multiple clinical scenarios (Sikorski et al, 1987;Shafik et al, 1995;Sato et al, 1997;Shafik and Doss, 1999;O'Bichere et al, 2000;Gruber et al, 2001;Barber et al, 2002;Reitz et al, 2003;Mahakkanukrauh et al, 2005;Loukas et al, 2006). The path of the pudendal nerve is also important in pudendal nerve blocks through the penetration of the area with a needle (Roberts and Taylor, 1973;Thoumas et al, 1999).…”

“…We strongly believe that information is important in posterior sacral rhizotomy, hip artroscopy, pudendal canal decompression surgery in childhood. We also believe that it would be important in intrauterine operations associated with pudendal nerve (Huang et al, 1997;Kocher et al, 2005;Loukas et al, 2006) that might be performed in the future.…”

Surgical treatment of nervus pudendus

“…Loukas et al (20) described the relationship between the pudendal nerve and the sacrotuberous ligament emphasizing the presence of the falciform process of sacrotuberous ligament and its relevance in the pudendal nerve entrapment syndrome. If the pudendal nerve becomes entrapped between this ligament process and the sacrospinous ligament causing perineal pain, the sacrotuberous ligament is surgically severed to relieve the pain.…”

Aspectos Anatómicos y Topográficos del Nervio Pudendo en la Región Glútea

“…El nervio pudendo tiene una gran importancia clíni-ca ya que se utiliza en diversas situaciones tales como anestesia local durante el parto, electroestimulación del nervio en casos de incontinencia fecal o urinaria y en procedimientos quirúrgicos, para anestesia del perineo, cuando el nervio está comprimido por estructuras adyacentes (Juenemann et al, 1988;Choi et al, 2006;Loukas et al, 2006;Reitz et al, 2007). Por otra parte, se ha descrito que este nervio puede ser lesionado por estiramiento excesivo en partos traumáticos, lo que podría llevar a incontinencia urinaria o fecal (Moore & Dalley).…”