Choosing the right ligament for support is a critical decision in the surgical management of pelvic organ prolapse. Surgeons often debate whether the sacrospinous ligament (SSL) or the uterosacral ligament (USL) provides more robust support. A recent cadaveric study has now provided detailed insights into apical suspension biomechanical strength, comparing these two primary anchoring sites using different surgical instruments.

Comparing SSL and USL Support

Researchers conducted this biomechanical evaluation during a surgical competency workshop using fresh-frozen cadavers. They specifically tested the pullout strength of the ligaments when using the AnchorSure System and the Miya hook ligature carrier. The results were quite revealing. The sacrospinous ligament demonstrated a mean load at failure of 44.0 ± 15.9 N. In contrast, the uterosacral ligament showed a significantly lower mean pullout strength of only 16.0 ± 10.0 N. Therefore, the SSL appears to offer a much stronger foundation for apical support compared to the USL.

Clinical Impact of Apical Suspension Biomechanical Strength

Understanding apical suspension biomechanical strength is essential for improving surgical outcomes in women with advanced prolapse. While clinical trials like the OPTIMAL study show similar long-term failure rates between SSL and USL suspensions, this biomechanical data suggests that the SSL is inherently more resistant to pullout forces. However, surgeons must balance this strength against the specific risks of each procedure. For instance, SSL fixation carries a higher risk of gluteal pain, while USL suspension is more frequently associated with ureteral obstruction. Consequently, the choice of procedure should involve a thorough assessment of the patient's anatomy and specific risk factors.

Study Methodology and Tools

The study utilized eight fresh-frozen cadavers to simulate real surgical conditions. For SSL fixation, the AnchorSure System (SSLF-t) was applied to the right SSL in most cases. Additionally, the Miya hook (SSLF-m) was used for bilateral SSL and USL suspension in other specimens. By measuring the maximum load at failure with a Newton meter, the team provided objective evidence that the sacrospinous ligament is a superior anchoring point for apical suspension in terms of raw mechanical strength.

Frequently Asked Questions

Which ligament provides higher pullout strength in apical suspension?

According to this biomechanical study, the sacrospinous ligament (SSL) provides significantly higher pullout strength (44.0 N) compared to the uterosacral ligament (16.0 N).

Does higher biomechanical strength always mean better clinical outcomes?

Not necessarily. While the SSL is mechanically stronger, clinical success also depends on surgical technique, patient healing, and the avoidance of complications like nerve injury or ureteral kinking.

What tools were used to measure ligament strength in this study?

The researchers used the AnchorSure System and the Miya hook ligature carrier to secure the ligaments, measuring the failure load with a Newton meter.

Disclaimer: This content is for informational and educational purposes only and does not constitute medical advice. It is not a substitute for professional medical judgment, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Refer to the latest local and national guidelines for clinical practice.

References

1. Lo TS et al. Pullout testing for sacrospinous ligament and uterosacral ligament in apical suspension: A cadaveric biomechanical study. Int J Gynaecol Obstet. 2026 Apr 27. doi: 10.1002/ijgo.71036. PMID: 42037521.

2. Jelovsek JE et al. Five-Year Outcomes of Uterosacral Ligament Suspension vs Sacrospinous Ligament Fixation for Pelvic Organ Prolapse: A Randomized Clinical Trial. JAMA. 2018;319(15):1554-1565.

3. Lee TG, Unlu BS. Sacrospinous ligament suspension and uterosacral ligament suspension in the treatment of apical prolapse. Gynecol Pelvic Med. 2020;3:34.