Achilles tendon rupture repair: Biomechanical comparison of the locking block modified Krackow technique and the Giftbox technique.

Abstract

Open Giftbox repair of the Achilles tendon has good biomechanical advantages, but it is not minimally invasive. We designed a peritendon fixation technique, the "Locking Block Modified Krackow" (LBMK) technique, to meet minimally invasive needs. This study used a simulated protocol of early rehabilitation to compare the biomechanics of LBMK with those of the Giftbox technique. Twenty fresh bovine Achilles tendon specimens were randomly assigned to either the LBMK group or the Giftbox group. The LBMK technique and the Giftbox technique were used as the main suture configurations, and transverse sutures were used as secondary suture configurations in both groups. Each repaired specimen was subjected to two cyclic loading protocols (20-100 N, 20-190 N). The gapping between the tendon ends was measured after each stage of loading. Finally, all specimens underwent a load-to-failure test at a stretching rate of 25 mm/s. After the first loading stage, the mean tendon gapping was 0.76±0.44 mm in the LBMK group and 0.86 ± 0.47 mm in the Giftbox group (p = 0.620). After the second loading test, the average gapping measures of the LBMK and Giftbox groups were 3.8 ± 1.9 mm and 4.2 ± 2.2 mm, respectively (p = 0.466). Finally, the catastrophic load to failure was 732.8 ± 138 N in the LBMK group and 645.5 ± 121 N in the Giftbox group. The difference was statistically significant (p = 0.023). Both the LBMK and Giftbox techniques meet the requirements of early rehabilitation, but the suture strength in the LBMK group was significantly higher than that in the Giftbox group.