Tendon repair with the strengthened modified Kessler, modified Kessler, and Savage suture techniques: a biomechanical comparison

Objectives: The aim of the study was to develop a suture technique that would be simple and easy to perform, but also strong enough to resist the strength formed during early active exercise protocols. Methods: Thirty flexor digitorum profundus muscle tendons were obtained from lambs aged 12 to 16 months. The tendons were assigned to three in situ repair groups, including the modified Kessler tech¬nique, six-strand Savage technique, and a strengthened modified Kessler technique, all combined with an epi- tendinous suture. Each group was subjected to biome- chanical tests and the maximum strength of the tendons to rupture and the power exerted to yield a 3-mm sepa¬ration were recorded. Results: The mean strengths of the tendons repaired with the modified Kessler technique for 3-mm separation and rupture were 29.9+2.9 N and 37.0+4.0 N, respectively. The corresponding forces were 39.1+6.7 N and 51.3+6.1 N with the six-strand Savage technique, and 59.9+8.3 N and 69.0+8.7 N with the strengthened modified Kessler tech¬nique, respectively. Forces to produce a 3-mm separation and rupture were significantly higher with the strengthened modified Kessler repair, whereas the lowest forces were seen with the modified Kessler technique (p<0.001). Conclusion: Tendon repair with the strengthened modi¬fied Kessler technique provides the highest resistance to both 3-mm separation and rupture. These biomechanical properties may allow safe and active motion without any gap formation in the repair area.