The Nice knot as an improvement on current knot options: A mechanical analysis.

PURPOSE: There is currently a wide range of suture knots used in rotator cuff repair. The purpose of this study was to compare a new type of self-locking sliding knot called the Nice knot to the self-locking and sliding Nicky's knot.

METHODS

Nice knots and Nicky's knots were tied and subjected to mechanical testing including a pure traction stress and a series of dynamic stresses. Both knots were tied using standard braided suture and reinforced braided suture. The responses to these stresses were measured in the amount of elongation of the knot, maximum effort needed for failure, stiffness of construct and dynamic stiffness.

RESULTS

With both knots the standard suture had a lower amount of elongation during the dynamic tests than the reinforced braided suture. The reinforced braided suture showed superior results during maximal effort in the pure traction tests. An increased failure rate occurred due to elongation when a dynamic stress was applied to the reinforced suture in both knot types. During dynamic testing the Nice knot showed a decrease in the amount of elongation (P<0.001).

CONCLUSIONS

The Nice knot provides a sliding locking knot option which can decrease the risk of elongation during dynamic stress.

LEVEL OF EVIDENCE: Basic Science Study, Biomechanical Study.