Mechanical characteristics of four allograft tendon-to-muscle anastomotic techniques

Four methods of allograft tendon-to-muscle anastomosis were tested in single cycle distraction to failure using 10 anastomosed ovine calcaneal tendon-biceps brachii units. The tendon-muscle units were compared to intact ovine biceps brachii muscle units. Methods of tendon-to-muscle anastomosis were derived from modifications of existing muscle tendon repair and tenorrhaphy techniques. Load to failure (N), stiffness (N/cm), distraction (cm), and modes of failure were recorded. Of the four methods tested, the side-to-side technique demonstrated the highest load to failure (152.1 N), the greatest stiffness (17.6 N/cm), the least distraction (2.99 cm) before failure, and the least amount of muscle tissue trauma at failure. Results indicate that, of the methods tested, the side-to-side technique offers the greatest initial stability and should therefore allow adequate revascularization and healing of the anastomosis site.