Comparison of Loop-Tendon Versus End-Weave Methods for Tendon Transfer or Grafting in Rabbits

PurposeThe loop-tendon method for the stabilization of tendon transfers or grafts has been demonstrated previously to have greater initial tensile strength than that of the end-weave method. To our knowledge, a comparison of the mechanical strengths of these methods over the early postoperative period has not been made. The purpose of this study was to compare the mechanical strengths of loop-tendon and end-weave methods of repair during the early postoperative period in rabbit hind limb tendons.MethodsIn bilateral hind limbs of 30 New Zealand white rabbits of an average weight of 3.5 kg, a distally cut gastrocnemius Achilles' tendon and a proximally cut flexor digitorum superficialis tendon were connected to each other by using the loop-tendon method with 5 stitches in one limb and a 1-pass end-weave method in the contralateral limb. Postoperatively, all rabbits were immobilized by a short-leg cylinder cast. Six rabbits were killed at each of the following time points: immediately after surgery (baseline) and at 1, 2, 3, and 4 weeks postoperatively. Repaired tendons were harvested and were loaded to failure in a tensile load-testing machine to record the ultimate strength and to calculate the absorbed energy.ResultsUltimate tensile loads were significantly higher in the loop-tendon method group than in the end-weave group from baseline to 3 weeks postoperatively, but there was no difference at 4 weeks postoperatively. During the postoperative period, the ultimate tensile load and absorbed energy decreased over the first 2 weeks postoperatively and then increased to reach baseline strengths at 3 weeks postoperatively in both groups.ConclusionsThe loop-tendon method provided greater strength than that of the end-weave method during the early postoperative period in rabbit tendons. The loop-tendon method may provide greater surgical repair strength during the early postoperative rehabilitation period than the end-weave method.