Abstract
During the development and early use of the First Generation of Universal Total Knee Replacement Instruments, those instruments supplied with the PCA knee and also available for use with the Kinematic and Total Condylar knees, David Hungerford and I noticed our imperfection in balancing some varus and valgus deformed total knee patients.
We decided to start ligament tightening procedures to address this problem.
I became impressed with the potential difficulty of simply grasping the medial capsular ligamentous sleeve and pulling it distally on the proximal tibia so that it could be stapled in place. I thought that use of a suture and then incorporation of that suture with a staple or screw could enhance the fixation.
The tissue we were working with and are now talking about is rather thin, 1mm to 2mm, flat and broad with longitudinal fibers running in a caudad-cephalad direction.
I wanted some way to grab these longitudinal fibers and exert a distal pull without having the suture material pull through. This suggested the use of a locking loop, analogous to what I had seen in my training when locking stitches were commonly used on different layers of wound closure. I developed in my head the picture of a row of locking loops and then saw the cross-over to the other side which revealed the entire structure with trailing tails.
At this writing, I am uncertain of the year, but I am thinking it was 1982.
Soon after that I illustrated it with OR suture thru paper and then began using it in surgery.
I felt that publication would require studies of relative pull-out strength, and we added an injection study to look at possible influence of the tissue vascularity.
For tensile strength we used #5 Ethibond in bovine xenograft material, stapled and sewn to wood. In summary, different from individual stitches or stapling without stitching, The K-stitch fails at the suture material and not by pulling the tissue. This statement is true when the suture reasonably matches the heft or thickness and strength of the soft tissue. Otherwise one is dealing with suture that is overpoweringly stronger than the tissues being fixed or held.
Clearly this stitch has found common application in Achilles tendon repair and a wide variety of other applications. My own most common use is with re-attachment of the gluteus minimus tendon after an anterolateral total hip exposure.
I imagine that this suture is used or at least known by all orthopaedic surgeons with one exception, spine surgeons. I just do not see an application in their surgery. However, some of the younger ones will know it from their general orthopaedic training.
A video is shown of the technique and it is emphasised that the suture need not be used so that it loops the edge of a tendon. It may just as easily and helpfully be used on a broader surface as shown.
