Direct suturing quadriceps tendon to a continuous loop with a suspensory button provides biomechanically superior fixation in ACL reconstruction

Abstract

PurposeTo compare the biomechanical strength of different fixation configurations using suspensory buttons in a soft‐tissue quadriceps tendon (QT) grafts in anterior cruciate ligament (ACL) reconstruction. MethodsForty bovine QTs, 6‐cm long and 10‐mm wide, were allocated into four groups with different suture configurations using suspensory buttons (n = 10 in each group): Group A, a baseball suture with a knot tied to the continuous loop with a suspensory button; Group B, same configuration as in Group A but with the knot tied at the opposite end of the baseball suture; Group C, a continuous loop with a suspensory button stitched directly to the QT with simple sutures, and Group D, a baseball suture tied directly to a suspensory button. Biomechanical testing was performed by preloading followed by cyclic loading for 500 cycles between 10 and 100 N. The length of elongation (mm) and maximum load to failure (N) were recorded, and compared among the four groups. ResultsGroup C showed significantly smaller elongation (4.1 mm [95% CI 3.1–5.2]) than Group A (8.2 mm [95% CI 7.0–9.4]), Group B (10.5 mm [95% CI 7.7–13.3]), and Group D (8.5 mm [95% CI 7.0–9.9]) (A–C; P = 0.004, B–C; P = 0.0001, C–D; P = 0.0018). The maximum load to failure in Group C (386 N [95%CI 306–466]) was significantly higher than that in Group A (196 N [95% CI 141–251]), Group B (226 N [95% CI 164–289]), and Group D (212 N [95%CI 171–253]) (A–C; P = 0.0001, B–C; P = 0.0009, C–D; P = 0.0002). No significant differences were observed between Group A, B, and D in terms of elongation and maximum load to failure. ConclusionThe soft‐tissue QT graft fixation configuration stitched directly to a continuous loop with suspensory button using simple sutures exhibits small elongation and high maximum load to failure among the four configurations. Regarding clinical relevance, direct suturing of the soft‐tissue QT to a continuous loop with a suspensory button may be advantageous for femoral fixation in ACL reconstruction from a biomechanical perspective, and warrant future development of a novel fixation device using this principle.

Speed whip ripstop technique during anterior cruciate ligament reconstruction using quadriceps tendon results in higher fixation strength

“…Red circle (dotted line): button is suspended on the frame Fig. 5 Failure mode of groups A, B, and C. In all cases, the ibers ruptured from the center of the tendon in groups A, B, and C (a group A; b group B; and c group C) buttons in soft-tissue QT grafts and reported that direct suturing of the suspensory button device was superior from a biomechanical perspective [11].…”

“…It is particularly important that to make sure that the tendon is not damaged and that the graft does not stretch and has sufficient strength to prevent graft failure [2]. Methods for securing soft‐tissue QT grafts have been reported [11, 16]. Michel et al investigated suture and stitch type in cyclic and load‐to‐failure tests and found that the Krackow stitch with a doubled no.…”

“…The tensile protocol was based on previous reports [2, 11, 16]. Tensile tests were performed by MK using a material testing machine (Shimadzu Autograph AG–X Plus 1 kN, Kyoto, Japan).…”

“…Statistical significance was set at P < 0.05. The sample size was determined by power analysis based on the data from a previously reported pilot study [11, 15] using G*Power 3.1. The sample size calculation revealed that an elongation difference of 3 mm would be detectable in 3 groups with a sample size of 27 (9 in each group) using one‐way ANOVA (effect size = 0.6, α = 0.05, and power = 0.8).…”

“…A recent biomechanical study investigated the effects of different stitching methods and suture diameters on fixation of soft‐tissue QT grafts [16]. Kamada et al reported that direct stitching to a suspensory button device may be better from a biomechanical perspective [11]. However, the biomechanical strength of fixation configurations using a suspensory button with an adjustable loop has not been investigated and, thus, remains unknown.…”