Three-dimensional anatomy of the pelvic bone in bladder exstrophy: comparison between patients managed with osteotomy and pubic symphysis internal fixation using metal plates.

OBJECTIVES

To compare intrapelvic osseous dimensions in classic bladder exstrophy patients who underwent pelvic osteotomy and pubic symphysis internal fixation, using metal plates without osteotomy by defining intrapelvic angles and distances using three-dimensional computed tomography scan (3D-CT).

METHODS

Fourteen exstrophy patients who were operated with osteotomy (OST) and 19 patients who had undergone pubic approximation using metal plates (PLT) were enrolled in this study. 3D-CT was performed to measure 8 intrapelvic angles and 9 distances. In addition, a 3D-CT image of control group of 14 age- and sex-matched patients and the preoperative data of 12 cases (6 patients in each group) were considered to compare the bony aspects of exstrophy patients before and 6 months after surgery.

RESULTS

Sacroiliac joint angle, pubococcygeal angle, ischiopubic angle, pubic diastasis, and inter-triradiate distance were different from controls in both techniques. Iliac wing angle, however, was at near normal values in PLT group. The result of before-after comparison revealed significant changes in iliac wing angle, sacroiliac joint angle, and pubic diastasis in both groups.

CONCLUSIONS

Our study suggests that internal fixation of pubic arch using metal plates in bladder exstrophy may be as effective as the currently accepted osteotomy-containing techniques from the standpoint of intrapelvic osseous dimensions and angles. Modification of our new pubic approximation technique is essential to better recapitulate the anatomy of the normal bony pelvis.