Sunday fun fact: Did you know that the uterosacral ligament was found to extend further on the right, although similar on both sides?
n a study in healthy women, the origin and insertion points exhibited greater anatomic variation than the name Uterosacral ligament would imply.
The rectouterine ligaments, also known as the posterior ligaments (uterosacral ligaments), are part of the integrated system that supports the pelvic organs. Wikipedia describes them as travelling from the uterus to the anterior aspect of the sacrum.
The ligaments range in length from 10-50mm, the average being around 21+/-8mm. 63% of women were found to have the origin on the cervix and vagina, with smaller percentages found on the cervix or vagina alone. When looking at the insertion points for the uterosacral ligaments, just 7% were inserted onto the sacrum as described in anatomy books! 82% overlay the sacrospinous ligament/coccygeus muscle, 11% to the piriformis muscle, sciatic foramen or ischial spine.
(Article – Quantitative analysis of uterosacral ligament origin and insertion points by MRI)
The uterosacral ligaments are visceral ligaments with mesentery like structures. They contain vessels, nerves, connective and adipose tissue, lymphatics and support an organ through its connections and thickenings. The presence of these elements indicates that these structures are active and contractile under involuntary control. In addition, the smooth muscle found in the uterosacral ligament appears to be decreased in women with prolapse. Petros, 2011. The Integral system; Patients undergoing hysterectomy have atrophied uterosacral ligaments from the reduced blood supply.
Sacropsinous ligament and uterosacral ligament suspension are commonly used to treat pelvic organ prolapse.
Endometriosis affects 10-15% of women and 70% of women with chronic pelvic pain. Tissue thickening and adhesions occur. A common site for deep endometriosis is the Uterosacral ligaments. (Article – Ultrasound Obstet Gynecol 2020 – M. Leonardi DOI:10.1002/uog.20300)
Article – Anatomy and Histology of apical support: a literature review concerning the cardinal and uterosacral ligaments. 2012