Pullout strengths of sacral and vaginal attachment sites in cadavers

Objectives: The aim of the study was to test the pullout strengths of the vaginal and sacral attachment sites commonly used in sacrocolpopexy and sacrospinous ligament fixation, on fixed cadavers, using a precision biomechanical measuring device (load cell). Methods: Fifteen fixed, postmenopausal, female cadavers were dissected exposing the sacrospinous ligaments by layered dissections. Of the 15 cadavers, 10 were available for dissection of the presacral fascia. We exposed and sequentially tested the anterior longitudinal ligament and fascia over the sacral promontory, S1, S2, and S3 as well as the apical vagina. A 30-1b. force gauge transducer was used to measure the breaking force strengths of the structures tested Results: The mean pullout strengths at the attachment sites were: 33.2 ± 2.1 lbs at the sacral promontory, 23.4 ± 5.6 lbs at S1, 16.7 ± 8.5 lbs at S2, 10.5 ± 8.3 lbs at S3, and 27.1 ± 3.2 lbs at the sacrospinous ligament, whereas the mean pullout strength at the apical vaginal was 18.4 ± 5.3 lbs (P[r] <0.001) Conclusions: The pullout strength was the strongest at the sacral promontory. The breaking force progressively decreased distally along the sacral segments. The pullout strength of the sacral promontory was statistically stronger than the sacrospinous ligament, whereas the pullout strength at S3 was weaker than the sacrospinous ligament (P[r] <0.005).