Jigless knotless internal brace versus other open Achilles tendon repair under progressive rehabilitation protocol: A biomechanical study

Abstract

Background The jigless knotless internal brace surgery (JKIB), a modified minimal invasive surgery (MIS) for acute Achilles tendon injury, showed the advantage of sural-nerve injury prevention in MIS and superficial wound infection in open surgery in previous clinical research. However, to date, biomechanical testing remains not yet validated. Materials and methods Sixty porcine fresh Achilles tendons were used to compare the JKIB with other open surgery techniques, the four-strand Krackow suture (4sK) and triple-buddle suture (TBS) in biomechanic testing with cyclic loading at 1 Hz. This approach simulated a progressive rehabilitation protocol where 20-100N was applied in the first 1000 cycles, followed by 20-190N in the second 1000 cycles, and then 20-369N in the third 1000 cycles. The cycles to the repair gap 2mm, 5mm and 10mm were recorded. The survival cycles was defined as repair gap achieving 10mm. Results With respect to survived cycles, a significant difference was found among the three groups, in which the TBS was the most robust, followed by the JKIB and the 4sK, with mean survived cycles were 2639.3 +/- 263.55, 2073.6 +/- 319.92 and 1425.25 +/- 268.96, respectively. Significant difference was defined via a post hoc analysis with the Mann–Whitney U test after the Bonferroni correction (p < 0.017). Conclusions The TBS was the strongest suture structure in acute Achilles tendon repair. However, the JKIB could be an option in acute Achilles tendon repair with the MIS technique due to it being more robust than the 4sK, which has been favored in open repair.