TY - JOUR
T1 - Role of the Pubic Symphysis in Osseous Pelvic Development
T2 - A Novel Model of Bladder Exstrophy in Rabbits
AU - Cottrill, Ethan
AU - Klyce, Walter
AU - Pennington, Zach
AU - Ehresman, Jeff
AU - Di Carlo, Heather
AU - Gearhart, John P.
AU - Sponseller, Paul D.
N1 - Funding Information:
E.C. discloses grant support from National Institute on Aging (non– study-related). P.D.S. discloses personal fees from DePuy Synthes, Globus Medical, OrthoPediatrics, and the Journal of Bone and Joint Surgery (all non–study-related). The remaining authors declare no conflicts of interest.
Publisher Copyright:
© 2021 Lippincott Williams and Wilkins. All rights reserved.
PY - 2021/2
Y1 - 2021/2
N2 - Background:It has been posited that the osseous pelvic anomalies seen in patients with classic bladder exstrophy (CBE) result from disruption of the pubic symphysis. This hypothesis, however, has not been tested. In the present animal study, our objective was to determine whether the tension of the pubic symphysis helps maintain the shape of the pelvic ring, or whether the growing bones maintain a ring shape even without the tension of the symphysis.Methods:In total, 12 neonatal New Zealand White rabbits underwent pubic symphysiotomy (experimental group, n=9) or sham surgery (control group, n=3) on days 3 or 4 of life. Rabbits were scanned with cone-beam computed tomography at 1, 4, 12, and 20 weeks postoperatively to monitor changes in the following pelvic parameters, which are known to be altered in CBE: anterior segment angle, anterior segment length, intertriradiate distance, interpubic distance, and posterior segment angle. Changes within the experimental and control groups were evaluated using repeated-measures analysis of variance and post hoc Tukey honest significant difference testing. Two-tailed t tests were used to compare treatment groups at each time point.Results:Both groups showed increases in anterior segment length and intertriradiate distance during the study period; rabbits in the experimental group also showed a steady increase in interpubic distance (F=43.9; P<0.001). Experimental rabbits had significantly larger mean values for anterior segment angle, intertriradiate distance, interpubic distance, and posterior segment angle than did control rabbits at all time points. We found no difference in mean anterior segment length between control and experimental groups at any time point. The difference in interpubic distance was particularly pronounced by 20 weeks (experimental group, 13±2.7 mm; control group, 1.1±0.1 mm; P<0.001).Conclusions:The pubic symphysis is essential for normal pelvic development. Its absence led to early pelvic angulation and progressive pubic separation in a rabbit model. However, we found no significant difference in the mean anterior segment length, and it is likely that other factors are also implicated in the growth disturbance seen in CBE.Level of Evidence:Level V.
AB - Background:It has been posited that the osseous pelvic anomalies seen in patients with classic bladder exstrophy (CBE) result from disruption of the pubic symphysis. This hypothesis, however, has not been tested. In the present animal study, our objective was to determine whether the tension of the pubic symphysis helps maintain the shape of the pelvic ring, or whether the growing bones maintain a ring shape even without the tension of the symphysis.Methods:In total, 12 neonatal New Zealand White rabbits underwent pubic symphysiotomy (experimental group, n=9) or sham surgery (control group, n=3) on days 3 or 4 of life. Rabbits were scanned with cone-beam computed tomography at 1, 4, 12, and 20 weeks postoperatively to monitor changes in the following pelvic parameters, which are known to be altered in CBE: anterior segment angle, anterior segment length, intertriradiate distance, interpubic distance, and posterior segment angle. Changes within the experimental and control groups were evaluated using repeated-measures analysis of variance and post hoc Tukey honest significant difference testing. Two-tailed t tests were used to compare treatment groups at each time point.Results:Both groups showed increases in anterior segment length and intertriradiate distance during the study period; rabbits in the experimental group also showed a steady increase in interpubic distance (F=43.9; P<0.001). Experimental rabbits had significantly larger mean values for anterior segment angle, intertriradiate distance, interpubic distance, and posterior segment angle than did control rabbits at all time points. We found no difference in mean anterior segment length between control and experimental groups at any time point. The difference in interpubic distance was particularly pronounced by 20 weeks (experimental group, 13±2.7 mm; control group, 1.1±0.1 mm; P<0.001).Conclusions:The pubic symphysis is essential for normal pelvic development. Its absence led to early pelvic angulation and progressive pubic separation in a rabbit model. However, we found no significant difference in the mean anterior segment length, and it is likely that other factors are also implicated in the growth disturbance seen in CBE.Level of Evidence:Level V.
KW - bladder exstrophy
KW - congenital defect
KW - neonatal medicine
KW - pubic symphysis
KW - rabbit model
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U2 - 10.1097/BPO.0000000000001698
DO - 10.1097/BPO.0000000000001698
M3 - Article
C2 - 33136931
AN - SCOPUS:85095841137
SN - 0271-6798
VL - 41
SP - E181-E187
JO - Journal of Pediatric Orthopaedics
JF - Journal of Pediatric Orthopaedics
IS - 2
ER -