Mechanical comparison of two knots and two crimp systems for securing nylon line used for extra-articular stabilization of the canine stifle.
OBJECTIVE
To compare mechanical properties of knotted and crimped nylon loops.


METHODS
In vitro mechanical evaluation.


METHODS
Loops of 27 kg-test nylon leader. Single strand-clamped square knot compared with 2 crimp systems. Two strand--self-locking knot compared with 2 crimped loops.


METHODS
(a) Single pull to failure (n = 10) at 500 mm/min. Initial loop tension (N), peak load (N), peak elongation (mm), stiffness of the linear portion of the curve (N/mm), and failure mode were recorded. (b) Incremental cyclic loading to failure (n = 5)--each loop was cycled 5 times to 100 N at a loading rate of 200 mm/min. Cycling was repeated, with the load increased by 50 N after each set. Elongation (mm), tension remaining (N), and after permanent deformation was present, elongation at 10 N (mm) were measured.


RESULTS
Initial tension and stiffness were greater for crimped loops when compared with knotted loops. There were no differences between crimped loops. The self-locking knot elongated more, and was less stiff, when compared with 2 crimped loops. With incremental loading, knotted loops elongated more than crimped loops. The tension remaining in the loop fell below 10 N more quickly for knotted loops compared with crimped loops.


CONCLUSIONS
Crimped loops are stiffer, and resist both static and cyclic load more effectively before becoming permanently elongated, when compared with knotted loops.


CONCLUSIONS
Stifle stability will be maintained more effectively by crimped nylon loops when compared with knotted loops.
Vianna
Maria L
ML
Department of Clinical Sciences, North Carolina State University, Raleigh, 27606, USA.
Roe
Simon C
SC
D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs / Q000601:surgery*; D007593:Joint Instability / Q000601:surgery / Q000662:veterinary*; D009757:Nylons; D013264:Stifle / Q000601:surgery*; D013525:Surgical Instruments / Q000592:standards / Q000662:veterinary*; D013536:Suture Techniques / Q000662:veterinary*; D013718:Tensile Strength
D009757:Nylons