A novel repair method for the treatment of acute Achilles tendon rupture with minimally invasive approach using button implant: a biomechanical study.

ABSTRACT

BACKGROUND: Minimally invasive Q3 repair has been proposed for acute Achilles tendon rupture with low rate of complications. However there are still controversies about optimal technique. In this study we aimed to describe Endobutton-assisted modified Bunnell configuration as a new Achilles tendon repair technique and evaluate its biomechanical properties comparing with native tendon and Krackow technique. METHODS: 27 ovine Achilles tendons were obtained and randomly placed into 3 groups with 9 specimens ineach. The Achilles tendons were repaired with Endobutton-assisted modified Bunnell technique in group 1, Krackow suture technique in group 2 and group 3 was defined as the control group including native tendons. Unidirectional tensile loading to failure was performed at 25mm/min. Biomechanicalproperties such as peak force to failure (N), stress at peak (MPa), elongation at failure, and Young'smodulus (GPa) was measured for each group. All groups were compared with each other using one-wayANOVA followed by the Tukey HSD multiple comparison test (a=0.05). RESULTS: The average peak force (N) to failure of group 1 and group 2 and control group was 415.6±57.6, 268.1±65.2 and 704.5±85.8, respectively. There was no statistically significant difference between native tendon and group 1 for the amount elongation at failure (p>0.05). CONCLUSIONS: Regarding the results, we concluded that Endobutton-assisted modified Bunnell technique provides stronger fixation than conventional techniques. It may allow early range of motion and can be easily applied in minimally invasive and percutaneous methods particularly for cases with poor quality tendon at the distal part of rupture. LEVEL OF EVIDENCE Level II, Biomechanical research study.