Editorial Message: When Is A Knot Not a Knot?

Dear Readers:   As a young surgeon, I was taught the value of tying secure knots, and the gold standard for surgeons was the square knot. I practiced tying square knots with both hands, one-handed, left-handed, right-handed, and without looking! Almost every doorknob, cabinet knob, and drawer pull had lengths of string attached where I had practiced tying knots. One of the filing cabinets I have had since medical school still has a length of string on the handle with hundreds of knots from my practicing while studying. I was very proud to be an accomplished square knot tier. You can imagine my surprise when I learned that, when pulled by one of the two ends, a perfectly executed square knot is converted into two half hitch knots; after trying this on several knots, I found that it was true.   A square knot is a great knot when there is no stress applied to it, but once it is placed under tension, it is no longer a square knot. With that in mind, I had to be content knowing my knots would be acceptable if they just held and did not slip.   Recently, Aanning and co-authors reported that, in addition to square knots placed under tension being converted to half hitch knots, the change in configuration results in damage to the suture material.^1,2 This damage occurs in monofilament as well as multifilament suture materials, and can result in breakage of the suture at the site where the knot twists from its square configuration to the half hitch configuration. This breakage has been implicated in abdominal wound dehiscence,³ disrupted arterial repairs, and anastomoses,⁴ as well as suture breakdown in cardiac operations.⁵ What does one do when the gold standard is suddenly found to be unreliable, and, in many cases, harmful? In this situation, it is just a matter of changing the way the surgeon ties knots. It is recommended that, instead of using square knots, the surgeon anchor sutures with half hitch knots or with granny knots from the beginning, both of which maintain their strength and integrity.²   What does this have to do with wound care? I assume a number of us doing wound care use sutures and sewing techniques on a regular basis. We need to adapt our techniques to best serve our patients. But an analogy can also be made about our reaction to pressure and stress. For example, we have many useful techniques with which to evaluate and treat patients that are coming under scrutiny by those outside of wound care. We have the evidence to prove these techniques are useful and beneficial to our patients, but what will we do when stress and pressure are applied to use them selectively, or not at all?   This pressure can come in the form of “required cost savings,” “implied use of too much care for our patients,” or even “seeing too many patients.” The pressure may be subtle or blatant, but it will come. If enough pressure is applied, will we give in and, like the square knot suture, break, resulting in damage and harm to our patients? I encourage you to perform a self-evaluation and determine in advance how you will react to such pressure. Will you stand and be counted as doing what is right for our patients, or will you be undone by the pressure, and possibly break under the stress? Our time to truly make a difference for our patients is now.

References

1. Aanning HL, Hass T, Jorgensen DR, Wulf CA. Square not a running knot. J Am Coll S Surg. 2007;204(3):422-425. 2. Aanning HL, Van Osdol A, Allamargot C, et al. Running sutures anchored with square knots are unreliable. Am J Surg. 2012;204(3):384-388. 3. van Ramshorst GH, Nieuwenhuizen J, Hop WC, et al. Adbominal wound dehiscence in adults: development and validation of a risk model. World J Surg. 2012;34(1):20-27. 4. Calhoun TR, Kitten CM. Polypropylene suture--is it safe? J Vasc Surg. 1986;4(1):98-100. 5. Carr JA, Savage ED. Aortic valve repair for aortic insufficiency in adults: a contemporary review and comparison with replacement techniques. Eur J Cardiothorac Surg. 2004;25(1):6-15.