The role of osteotomy in surgical repair of bladder exstrophy.

Classic bladder exstrophy (CBE) patients are born with a pubic diastasis that increases steadily with age from a mean value of 4 cm at birth to a mean of 8 cm at age 10, compared with a mean normal width of the pubic symphysis of 0.6 cm at all ages. The width of the sacrum and length of the posterior (iliac) segment of the pelvis in CBE patients are normal; however, the anterior (ischiopubic) segment of the pelvis is a mean 30% shorter and both the anterior and posterior segments are externally rotated compared to controls. The main role of osteotomy in treatment of CBE appears to be to relax tension on the bladder and repaired abdominal wall during wound-healing. Anterior innominate osteotomy with optional posterior vertical iliac osteotomy presents several advantages over the prior conventional technique of posterior iliac osteotomy. These include (a) less intraoperative blood loss, (b) better apposition and mobility of the pubic rami at the time of closure, (c) allowance for placement of an external fixator under direct vision, (d) allowance for secure external fixation in children over 6 months old, and (e) no requirement to turn the patient during the operation.