Cyclic Loading of 3 Achilles Tendon Repairs Simulating Early Postoperative Forces

Abstract

Epitendinous cross-stitch weave augmentation of Achilles tendon repairs may better allow for early stretching and ambulation after Achilles tendon repair.

A Biomechanical Comparison of an Open Repair and 3 Minimally Invasive Percutaneous Achilles Tendon Repair Techniques During a Simulated, Progressive Rehabilitation Protocol

“…Results demonstrated the reduced strength of Achillon repaired tendons and a susceptibility to early repair elongation compared with both augmented and nonaugmented Krackow repairs. 22 Simulated Achillon repairs consistently failed during the first loading stage (20-100 N), while nonaugmented and augmented Krackow repairs primarily failed during the second (20-190 N) and third (20-369 N) stages, respectively. In the present study, no percutaneous repairs failed during the first loading stage (20- 100 N).…”

“…Loads were selected to mimic a progressive, postoperative rehabilitation protocol and were based on previous literature describing load ranges experienced by the Achilles tendon during passive ankle flexion (20-100 N) and walking in a cam walker with (190 N) and without (369 N) a 1-inch heel lift. 1,7,22,29 Load and displacement were monitored and recorded continuously throughout testing and reported as means 6 SDs. Repair failure was defined either as a precipitous drop in measured load, resulting from complete failure at the suture-tendon interface, or repair elongation that exceeded the maximum actuator travel distance of the tensile testing machine (.5 cm).…”

A Biomechanical Comparison of Limited Open Versus Krackow Repair for Achilles Tendon Rupture

“…4,22 Prior studies have used initial linear stiffness as a surrogate measure of gapping. 10 The initial linear stiffness (N/mm) estimates the force (N) required to create a gap of 1 mm.…”

“…Recent studies show that adding epitendinous suture reinforcement may improve tensile strength, gap resistance, and apposition of frayed tendon ends. 22,27 Lee et al showed in a cadaveric model that Krackow repairs with an epitendinous cross-stitch weave tolerated more cycles before gapping than nonaugmented Krackow repairs (2208 vs 502 cycles) (P ¼ .024). 21 In the present study, it is possible that augmentation contributed to the greater initial linear stiffness seen after open repair.…”

“…Although we did not collect data on displacement directly, The open repair consisted of (A) a 2-strand Krackow repair augmented with (B) epitendinous weave. After the Krackow stitch, the epitendinous weave was passed through the tendon 2.5 cm from its torn edge as described by Lee et al 22 (C) The PARS Achilles Jig System (Arthrex). The PARS repair consisted of 2 simple transverse and 1 locking suture.…”