Assessment of the Resistance of Several Suture Techniques in Human Cadaver Achilles Tendons

Many treatments are available for acute Achilles tendon ruptures, conservative and surgical, with none superior to another. For surgical treatment, one can use various techniques. Recent studies have shown that double stitches are superior to simple sutures. Therefore, in the present study, we sought to determine the suture technique that is the most resistant to rupture. We performed an experimental anatomic study with 27 fresh-frozen human cadaveric Achilles tendons obtained through the body donation program of the University of Barcelona, testing the maximum strength. We simulated a rupture by performing resection in the middle portion of the tendon, 4 cm proximal to the calcaneus insertion. We then evaluated the double Kessler, double Bunnell, Krackow, and percutaneous Ma and Griffith technique. We used absorbable suture (polydioxanone no. 1) with all the techniques. Traction was performed using a machine that pulls the tendon at 10 to 100 N in 1000 repetitive cycles. Statistical analysis was performed using the χ² test and analysis of variance, with the 95% confidence intervals (p < .05). All repairs failed at the site of the suture knots, with none pulling out through the substance of the tendon. We found no significant differences among the different open suture techniques (p > .05). The Krackow suture presented with superior resistance, with a rupture rate 16.70% but with a mean elongation of 7.11 mm. The double Bunnell suture had the same rupture rate as the Krakow suture (16.70%) but with an inferior mean elongation of 4.53 mm. The Krackow and Bunnell suture were superior in endurance, strength of failure, and primary stability compared with the other suture types. However, the former presented with greater tendon elongation, although the difference was not statistically significant. Therefore, according to our findings and the published data, we recommend double Bunnell sutures for the surgical treatment of acute Achilles tendon rupture.