Optimum locations of the locking loop and knot in tendon sutures based on the locking Kessler method

We investigated the factors that influence tensile strength and resistance to gap formation at the repair site of tendon suture (stiffness) by comparing (1) the location of the locking loops and (2) the location of the knot.

Transected bovine tendons of the medial gastrocnemius (9-11 x 14-16 mm diameter) were sutured with a modified locking Kessler method with a USP (United States Pharmacopeial convention) 2 polyester multifilament suture (0.500-0.599 mm) and loaded to failure using an Instron 5565 tensiometer. The locking loops were located on either the upper surface facing the operator or on side portions of the tendon. The knot was positioned either close to or far from the tendon stump.

The locations of the locking loops did not influence the tensile strength; however, the stiffness of the side loop suture (5.70 +/- 0.09 N/mm) was significantly higher than that of the upper surface loop suture (5.17 +/- 0.10 N/mm). Regarding the knot location, the tensile strength with the knot far from the tendon stump (195.1 +/- 4.8 N) was significantly higher than that with the knot close to the tendon stump (169.0 +/- 3.6 N), although the stiffness was unchanged by differences in knot location.

These data suggested that a greater tensile strength with less of a gap is obtained by (1) forming locking loops in the side portion of the tendon, and (2) forming knots far from the tendon stump.