The blood supply to the sacrotuberous ligament

Abstract

Knowledge of the vascular supply associated with the sacrotuberous ligament is incomplete, and at most attributed to a single coccygeal branch. Our aim was to investigate the sacrotuberous ligament vasculature with a focus on its origin and distribution. We dissected 21 hemipelvises (10 male and 11 female). The gluteus maximus was reflected medially, and a special emphasis was placed on the dissection of the vascular and neuronal structures. All specimens exhibited several (1-4) coccygeal arteries branching from the inferior gluteal artery penetrating the sacrotuberous ligament along its length. Seven specimens demonstrated the superior gluteal artery supplying sacral branches to the proximal superior border of the sacrotuberous ligament. Our study highlights several branches from a variety of origins as the supply to sacrotuberous ligament unlike previous reports stating only one vessel. Our results implicate surgical procedures in and around the area of the gluteal region such as decompressive procedures of the pudendal nerve, as it travels between the sacrotuberous and sacrospinous ligaments.

A systematic review of the morphology and function of the sacrotuberous ligament

“…Six studies have explored the morphometric characteristics of the STL, primarily focusing on its length, depth, and width (Table ). The mean length of the STL is variable ranging from 6.4 to 9.4 cm (Hammer et al ; Lai et al ; Seizeur et al ), although its mean depth (at the middle section of the ligament) is more consistent at 0.3–0.4 cm (Hammer et al ; Loukas et al ). The mean width of the STL has been assessed at three different locations, including its origin (4.9–7.6 cm), mid‐point (1.8–3.5 cm), and distal insertion (2.3–5.8 cm).…”

“…For example, Seizeur et al () obtained two measurements of STL length, from both its superolateral and inferolateral margins, relative to the ischial tuberosity. In contrast, Lai et al () considered the STL as a single distance between the middle width of its sacral portion and the ischial tuberosity.…”

“…In most cases, the vascular supply to the STL is reported as a secondary finding in anatomical investigations related to underlying mechanisms of pudendal nerve entrapment. However, three anatomical studies contribute specific information on the vascular aspects of the STL (Hammer et al ;Loukas et al ; Thompson et al ) and one provides a detailed description (Lai et al ). Two studies report that the coccygeal branch of the inferior gluteal artery penetrates the STL at numerous sites and exits the pelvis, as the coccygeal branch, through this ligament (Loukas et al ; Thompson et al ).…”

“…In a recent study by Lai et al (), the arterial supply of the STL was described based on findings from 21 hemipelves (16 cadavers, 8 males). They report that the STL is not exclusively supplied by the inferior gluteal artery as previously described.…”

“…Rather, both the inferior and the superior gluteal artery (coccygeal branches) cross the STL, in several locations close to the ischial tuberosity. The superior gluteal artery (sacral branches) pierces the STL near the sacrum supplying blood to the medial and proximal aspect of the STL, that is, the width of the ligament (Lai et al ). Interestingly, the morphology of the STL does not seem to influence the number of sacral or coccygeal branches.…”