An in vitro biomechanical comparison of the breaking strength and stiffness of polydioxanone (sizes 2, 7) and polyglactin 910 (sizes 3, 6) in the equine linea alba.
OBJECTIVE
To determine failure strength, stiffness, and failure mode of 4 suture materials in equine linea alba.


METHODS
Randomized complete block design.


METHODS
Linea albas collected from 12 adult horses (mean weight, 475 kg; mean age, 10 years).


METHODS
The ventral abdominal fascia, including the linea alba, was collected and bisected along the linea alba into right and left halves. Each half was divided into four, 5-cm sections extending from the umbilicus cranially, and randomly assigned to 1 of 4 suture materials: 2 polydioxanone (2 PD), 3 polyglactin 910 (3 PG), 6 polyglactin 910 (6 PG), and 7 polydioxanone (7 PD). A single cycle to failure test was performed on each specimen at a distraction rate of 100 mm/min. Differences in failure strength and stiffness for the materials were evaluated using a mixed linear model with significance set at P<.05.


RESULTS
In 94 of 96 test sections, constructs failed by suture failure. There were significant differences in failure strength (P<.0001) and stiffness (P<.001) among the suture/tissue constructs. 7 PD had the highest breaking strength (316.8 N) followed by 6 PG (281.3 N), 3 PG (229.9 N), and 2 PD (193.0 N). Six PG had the largest stiffness (14 N/mm) followed by 3 PG (12.7 N/mm), 7 PD (10.1 N/mm), and 2 PD (7.2 N/mm). Suture breaking strength and stiffness were not affected by linea or fascia thickness, individual horse, half of the linea alba, or abdominal wall position. Eighty-five (90.4%) suture loops failed adjacent the knot.


CONCLUSIONS
When tested in single cycle to failure, suture material was more likely to fail than the linea alba. Larger suture materials had higher breaking strengths than smaller suture materials and stiffness was also affected by suture material and size.


CONCLUSIONS
Given its high initial breaking strength and its relatively longer in vivo strength retention, 7 PD seems an appropriate choice of suture material for closure of the equine linea alba when maximal short-term failure strength is desired.
Fierheller
Erin E
EE
Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Sask., Canada.
Wilson
David G
DG
D000009:Abdominal Muscles / Q000502:physiology* / Q000601:surgery*; D000818:Animals; D001696:Biomechanical Phenomena; D002102:Cadaver; D000071938:Fasciotomy; D006736:Horses / Q000601:surgery*; D008422:Materials Testing / Q000662:veterinary; D016687:Polydioxanone / Q000592:standards*; D011098:Polyglactin 910 / Q000592:standards*; D011897:Random Allocation; D013529:Surgical Wound Dehiscence / Q000662:veterinary; D013536:Suture Techniques / Q000295:instrumentation / Q000662:veterinary; D013537:Sutures / Q000592:standards / Q000662:veterinary*
D016687:Polydioxanone; D011098:Polyglactin 910