Cyclic load and failure behavior of arthroscopic knots and high strength sutures.
OBJECTIVE
To compare the biomechanical performance of several different sutures by evaluating knot security and load to failure strength using different arthroscopic knots.


METHODS
Eight different No. 2 sutures (Ethibond [Ethicon, Somerville, NJ], FiberWire [Arthrex, Naples, FL], Orthocord [DePuy-Mitek, Norwood, MA], Hi-Fi [ConMed Linvatec, Largo, FL], Ultrabraid [Smith & Nephew, Andover, MA], ForceFiber [Stryker Endoscopy, San Jose, CA], MagnumWire [ArthroCare, Sunnyvale, CA], and MaxBraid PE [Arthrotek, Warsaw, IN]) were tied arthroscopically into standardized loops using 6 different knots (Weston, Tennessee slider, Duncan, SMC, Revo, and San Diego knot) 10 times each. The suture loops were pretensioned to 10N, cycled between 10N and 45N for 1,000 cycles, and loaded to failure. The failure load for each suture, each knot, and slippage trend during cyclic loading was recorded.


RESULTS
The Revo and SMC knots (group A) were stronger than the Tennessee and San Diego knots (group B), which were stronger than the Weston knot, which was stronger than the Duncan loop (P < .05). This pattern also coincided with the loads at which these knots slipped. Evaluating the sutures showed that Ethibond had lower failure loads than all other sutures and FiberWire showed statistically higher loads (P < .05). Duncan loops (97.5%) and Weston knots (86.3%) slipped more than other knots (P < .001), while the SMC and Revo knots slipped least. Ethibond sutures were least likely to slip.


CONCLUSIONS
The Duncan loop and Weston knot were more likely to slip than all other knots, and caution should be exercised when tying them with high-strength sutures. The Revo, Tennessee slider, San Diego, and SMC knots were least likely to slip (P < .001).


CONCLUSIONS
While stronger than braided polyester sutures, newer sutures containing ultra-high molecular weight polyethylene have a greater tendency to slip. Backing up knots with 4 reversed half hitches with switched posts does not guarantee knot security.
Barber
F Alan
FA
Plano Orthopedic and Sports Medicine Center, Plano, Texas 75093, USA.
Herbert
Morley A
MA
Beavis
R Cole
RC
D001182:Arthroscopy; D004868:Equipment Failure; D008422:Materials Testing; D008970:Molecular Weight; D011091:Polyesters; D020959:Polyethylene; D013314:Stress, Mechanical; D013536:Suture Techniques; D013537:Sutures; D016474:Weight-Bearing
D011091:Polyesters; D020959:Polyethylene