Reverse Flipping Technique: An Alternate Approach to Tie Reversing Half-Hitches on Alternating Posts

Abstract

Arthroscopic knot tying requires practice and attention to detail, especially tying the 3 reversing half-hitches on alternating posts (RHAPs) in a knot. Mistakes can occur that result in an unintentional tension (>10 N) applied to the wrapping suture limb, and by placing tension in the wrong limb, the previously "flipped" half-hitch is converted from a series of RHAPs into a series of identical half-hitches on the same post, thereby producing insecure knots or suture loops. This was hypothesized to be a source of knot failure by knot slippage. This error can be avoided by using a technique we describe as "reverse flipping," which purposely "flips" the half-hitch down at the main knot while tying the 3 RHAPs in a knot, and then the half-hitch is retightened using either a past-pointing or over-pointing technique. This way the surgeon can be absolutely sure that the half-hitch is tightened in the direction that it was intended to be placed, and can also prevent the unintentional tension applied to the wrapping suture limb that causes the half-hitch to "flip." However, caution should be used when tensioning the half-hitches; overtensioning (>40 N) during past-pointing or over-pointing could also potentially "flip" the previous half-hitch that has already been tightened and cause potential knot failure.

Fig 1

Reverse flipping technique steps. (A) The initial base knot of the surgeon's preference is slid down to the tissue using a knot pusher on the post limb; the first half-hitch is formed while maintaining tension on the post suture limb, which is then pushed down onto the base knot using the knot pusher until the loop seats on the main knot. (B) The half-hitch is tightened by using the over-pointing technique. (C) Tension then deliberately applies to the loop suture limb until a “flip” occurs. (D) The half-hitch is retightened again by using the past-pointing technique. (E) The second half-hitch is placed over the post suture limb again, but then the post switches by increasing tension on the loop suture limb. (F) The second half-hitch is tightened by using the past-pointing technique. (G) Tension then deliberately applies to the post limb until a “flip” occurs. (H) The half-hitch is retightened again by using the over-pointing technique. (I) The last half-hitch is then placed over the post suture limb again while maintaining tension on the post limb. (J) The half-hitch is retightened again by using the over-pointing technique. (K) Tension then deliberately applies to the loop limb until a “flip” occurs. (L) The half-hitch is retightened again by using the past-pointing technique.