Pubic symphysis repair strength in simulated bladder exstrophy using a sheep model.
OBJECTIVE
To investigate the mechanical strength of various pubic symphysis suture material in a simulated animal model of neonatal bladder exstrophy.


METHODS
Neonatal lamb pelves, which are the approximate size of neonatal human pelves, were used. Twenty-four neonatal lamb pelves were divided into four equal groups. A midline symphysotomy was made through the cartilaginous pubic symphysis in three groups and repaired using two figure-of-eight sutures (size 0) placed through the cartilaginous pubis using polypropylene, braided polyester, or polyglactin. The fourth group served as the control. The pelves were then tested to ultimate load in pure tension at a strain rate of 0.25 mm/s until failure.


RESULTS
There was a highly significant difference between the intact specimens and the repaired specimens (P = 0.0008). For the repaired specimens, there was a significant difference in the ultimate load normalized by pubic height between those repaired with polypropylene and polyglactin (P = 0.025), but not for those repaired with polypropylene and braided polyester (P = 0.11) or braided polyester and polyglactin (P = 0.11).


CONCLUSIONS
Braided resorbable sutures are recommended for pubic symphysis repair, because they have a lower tendency to cut out of the cartilage.
Urquhart
A G
AG
Orthopaedic Research Laboratory, University of Michigan School of Medicine, Ann Arbor 48109-0328, USA.
Frankenburg
E P
EP
Bloom
D A
DA
Loder
R T
RT
D000818:Animals; D000831:Animals, Newborn; D001746:Bladder Exstrophy; D011631:Pubic Symphysis; D012756:Sheep; D013536:Suture Techniques; D013718:Tensile Strength