Biomechanical Comparison of a Novel Multiplanar, Perpendicular Whipstitch With the Krackow Stitch and Standard Commercial Whipstitch

Abstract

Background: Using alternating orthogonal suture throws with the looped whipstitch technique may allow enhanced suture fixation. Hypothesis: It was hypothesized that this novel multiplanar, perpendicular looped whipstitch (MP) technique would have improved biomechanical properties compared with the standard looped whipstitch (WS) and Krackow stitch (KS). Study Design: Controlled laboratory study. Methods: A total of 30 cadaveric tibialis anterior tendons were randomly assigned into 3 groups of 10. Tendons were secured to a custom clamp, and the other end was sutured using 1 of 3 techniques: the KS, WS, or novel MP. The MP was performed with alternating orthogonal throws starting right to left, then front to back, left to right, and back to front. Each technique used 4 passes of No. 2 FiberWire spaced 5 mm apart and ending 10 mm from the tendon end. Tendons were preloaded to 5 N, pretensioned to 50 N at 100 mm/min for 3 cycles, returned to 5 N for 1 minute, cycled from 5 to 100 N at 200 mm/min for 100 cycles, and then loaded to failure at 20 mm/min. Elongation was recorded after pretensioning and cycling and was measured both across the suture-tendon interface and from the base of the suture-tendon interface to markings on the suture limbs (construct elongation). One-way analyses of variance were performed, with Bonferroni post hoc analysis when appropriate. Results: There were no differences in cross-sectional area or stiffness among the 3 techniques. The ultimate load for WS (183.33 ± 57.44 N) was less compared with both MP (270.76 ± 39.36 N) and KS (298.90 ± 25.94 N) ( P ≤ .001 for both). There was less construct elongation for KS compared with WS and MP for total displacement, measured from pretensioning to the end of cycling ( P < .001). All 3 techniques saw a decrease in length (shortening) at the suture-tendon interface during testing. There was more shortening at the suture-tendon interface for WS compared with KS ( P = .006). Conclusion: The KS appears superior, as it maximized strength while minimizing construct elongation or graft shortening. The ultimate load of the MP technique was greater than that of the standard technique but not significantly different from that of the KS technique. Clinical Relevance: The KS is preferred. If using a WS, multiplanar, perpendicular passes should be considered.

Whip-Lock Stitch Is Biomechanically Superior to Whipstitch for Semitendinosus Tendons

“…Elongation is another parameter that may have clinical value given that it has been shown to be a determinant of outcomes after Achilles tendon rupture. 3 , 34 , 35 It has also been associated with initial fixation to ensure tension is maintained until incorporation to native bone occurs. 13 , 36 The clinical threshold for failure has been cited in the literature as elongation greater than 3 mm.…”

“…Creating a stable soft-tissue suture construct may improve clinical outcomes by allowing early initiation of rehabilitation and providing stability during the healing phase. 1 , 2 , 3 Ultimately, the goals of soft-tissue suture repair or reconstruction include decreasing recovery time, restoring functionality, and achieving a successful return in terms of the patient’s quality of life. 4 Various types of ligament and tendon injuries require suturing to enable repair or reconstruction, and the most common include tears of the anterior cruciate ligament (ACL), biceps tendon, and Achilles tendon.…”

“…The 2 most prevalent stitching methods include the whipstitch (WS) and the Krackow stitch (KS). 3 Prior studies have tested the timing and biomechanics of the WS and KS techniques, but conclusions on which method is superior are divided, with some authors citing the speed benefits of the WS as the reason that this method is superior 7 , 9 but others citing that the strength benefits of the KS outweigh the additional time required. 4 , 10 , 11 …”

“…The WS was found to be time-efficient and to require the lowest number of needle holes 9 ; however, the suture construct may damage the tissue by shredding or “cheese wiring” because forces are concentrated along the centerline of the tissue. 3 , 7 In contrast, the KS has long been a gold standard 12 for superior biomechanical performance because the locking mechanism added to the suture may help to transfer load from the tissue to the sutures. 10 , 11 , 13 However, it can be time-consuming and requires a large number of needle holes, which may also create stress risers and inevitably damage the tissue.…”