Acetabular coverage in bladder exstrophy: role of 3-dimensional computed tomography.

We studied the acetabular coverage in bladder exstrophy patients and normal control children. The study included 13 patients with bladder exstrophy, who were divided according to their ages into group I below 5 years, group II between 5 and 10 years, and group III above 10 years of age. Four normal children served as controls, 2 were below 5 years, one was 7 and one was 12 years old. We measured the acetabular coverage (AC) and the center-edge-angle (CEA) by utilising the reconstructed 3-dimensional CT images. The mean right and left AC angles were 82 +/- 12 and 82 +/- 20 degrees in group-I, 107 +/- 15 and 103 +/- 17 in group-II and 119 +/- 24 and 116 +/- 22 in group-lII, respectively (p < 0.05). The mean right and left CEA angles were 33 +/- 4 and 32 +/- 4 degrees in group-I, 30 +/- 4 and 29 +/- 5 in group-II and 25 +/- 2 and 24 +/- 1 in group-III, respectively (p < 0.05). In controls, the mean right and left AC angles were 151 +/- 2 and 153 +/- 2 degrees for children below 5 years, 166 and 165 degrees in the 7 year-old child and 180 and 180 degrees in the 12 year-old child. The CEA angle ranged from 15 to 25 degrees. Acetabular coverage in bladder exstrophy patients is deficient during the first 5 years of life. Although it gradually improves over time, it does not reach to normal value.