Do Needleless Knots have Similar Strength as the Krackow Suture? An In Vitro Porcine Tendon Study

Abstract

Background Numerous needleless techniques for tendon graft fixation that feature several advantages have been reported. However, there are few studies that have compared the holding strength between the needleless techniques (rolling hitch and modified rolling hitch) and traditional suture methods. Questions/purposes To compare the tendon graft-holding strength of the rolling hitch and modified rolling hitch with the Krackow stitch in an in vitro porcine biomechanical model. Methods Thirty fresh-frozen porcine flexor profundus tendons were randomly divided into three groups of 10 specimens. The experimental procedure was designed to assess elongation of the suture-tendon construct across the needleless tendon-grasping techniques and the Krackow stitch. All suture configurations were completed with a braided nonabsorbable suture. Each tendon was pretensioned to 100 N for three cycles, cyclically loaded from 50 to 200 N for 200 cycles, and then finally loaded to failure. Elongation, load to failure, and mode of failure were recorded for each specimen.

The Biomechanical Properties of a High-Tensile Strength Tape for Tendon Graft Fixation Using the Krackow Configuration

“…A secure suture-tendon construct is especially important when a post tie fixation technique is used because the mitigating construct may potentially lead to graft loosening and affect graft healing. Numerous biomechanical studies have been conducted to obtain reliable suture-tendon constructs, 1 , 3 , 4 , 7 , 8 , 11 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 and using the Krackow suture technique accompanied with a high-tensile strength suture is currently the most popular method. Recently, a high-tensile strength tape was developed, which was reported to have greater knot security, ultimate load to failure, and tensile stiffness as compared to the high-tensile strength round core suture.…”

“…The parameters in the biomechanical testing protocol were in accordance to previous studies. 1,4,9,[15][16][17][18][19][20][21] All specimens were initially pretensioned to 100 N at a rate of 100 mm/min for 3 cycles and then preloaded to 50 N for 1 minute. After that, each specimen was cyclically loaded between 50 and 200 N with a cross-head speed of 200 mm/min for 200 cycles.…”

A Biomechanical Comparison of Six Suture Configurations for Soft Tissue–Based Graft Traction and Fixation

“…3,4,13 It is clearly not the quickest approach and the desire for a more efficient yet effective option has led to the development of many other stitch configurations. 1,6,8,14 The goals of a simpler and quicker construct are achieved by the SpeedTrap, WhipKnot, and Loop-in-loop constructs. Additionally considering tissue damage during the load to failure testing demonstrates that these three techniques are the least traumatic of those tested.…”

Editorial Commentary: The Krackow Stitch: More Than 30 Years of Tendon Repair and Still Holding Strong

“…2 Hong et al found no difference in cyclic load and load to failure between needleless knot techniques and Krackow configurations. 6 Ostrander et al found no difference to elongation in cyclic load between modified Krackow and modified locking Speedwhip stitch. 7 Gnandt et al show during a single load to failure that highetensile strength tape performs more favorably than highetensile strength suture, with a greater mean load to failure, in both the whip-and Krackow-stitch models.…”