The influence of triple pelvic osteotomy on birth canal size.

INTRODUCTION: The aim of this study was to investigate the influence of triple pelvic osteotomy on the internal pelvic dimensions and thus on the potential for normal vaginal delivery.

METHODS: Data were acquired by processing fixed anatomical specimens of 19 female pelves with maintained sacrotuberous and sacrospinous ligaments after unilateral and bilateral osteotomy, respectively. The specimens were measured and x-ray images and photographs were taken.

RESULTS: The dimensions in the plane of the pelvic inlet and the plane of the greatest pelvic dimension after unilateral osteotomy increased in 51%, remained unchanged in 34% and in 15% of cases they decreased. The most critical locations for the passage of fetus decreased in average from 0.016 cm in distantia interspinalis in the plane of the least pelvic dimension to 0.695 cm in distantia intertuberositas in the plane of the pelvic outlet. After bilateral osteotomy are decreases more significant from 0.226 cm (2.05%) to 1.00 cm (9.51%). Decreases we observed in the monitored dimensions were not so big in comparison to other published studies.

CONCLUSION: Results of this study confirm our hypothesis that unilateral triple pelvic osteotomy does not significantly narrow the bony birth canal and so it does not impede the ability to deliver per vias naturales in female patients with this surgical procedure in anamnesis. After bilateral triple osteotomy we would rather recommend Caesarean section.