Biomechanical Comparison of Krackow and Uchiyama Suture Techniques for Acute Tendon Repair in an Ex Vivo Porcine Model

Abstract

This study compared the maximum load to failure of Krackow and Uchiyama suture techniques in an acute tendon repair in an ex vivo porcine model. Achilles tendon rupture is a common injury in athletes and active individuals. In 2007, Uchiyama et al. published a case series of a modified operation for Achilles tendon ruptures. This technique is reported to allow strong and stable repair with subsequent early weight bearing and range of motion exercises. However, no biomechanical studies have been performed to compare this novel suturing technique to a standard like Krackow. Twenty freshly harvested porcine digital flexor tendons were transected transversely at the mid-substance. Ten were repaired with double-strand Krackow suture technique using non-absorbable polyester braided suture Ethibond®2. The other 10 tendons were further divided into bundles approximately 5 mm wide—2 proximal and 2 distal. The Uchiyama repair was completed by gathering each bundle by Bunell-like sutures using Ethibond®2-0. Biomechanical testing was conducted on the samples using a mechanical universal testing machine (Shimadzu® AGS-X Series). Longitudinal traction at an advancement rate of 0.85 mm/second was performed and maximum load to failure and mode of failure were statistically compared. The average maximum load to failure was not significantly different between the Krackow repair (119.18 N ± 37.4) and Uchiyama (112.98 ± 32.06) ( p = 0.34). All modes of failure were due to suture breakage. There is no significant difference between the maximum load to failure of Uchiyama and Krackow suture technique. Uchiyama suture technique may be an alternative to open repair of acute tendon of Achilles rupture. This warrants further studies to investigate other properties like failure to cyclic loading, tendon gapping, etc. In vivo studies may be geared toward effect of greater surface contact and smaller caliber sutures in tendon healing. Gonzales MRC, Italia KR, Canlas JRC, et al. Biomechanical Comparison of Krackow and Uchiyama Suture Techniques for Acute Tendon Repair in an Ex Vivo Porcine Model. J Foot Ankle Surg (Asia Pacific) 2021;8(1):8–11.