Zone II tendon repairs augmented with autogenous dorsal tendon graft: A biomechanical analysis

We investigated the biomechanical properties of a new technique for tendon repair that reinforces a standard suture with an autogenous tendon graft. A dynamic in situ testing apparatus was used to test 40 flexor digitorum pro fundus tendons harvested from fresh-frozen cadaver hands. The tendons were cut and repaired using 1 of 4 suture techniques: 2-strand modified Kessler, 4-strand modified Kessler, 6-strand modified Savage, and 2-strand modified Kessler augmented with autogenous dorsal tendon graft. The augmented repai r uses 1 slip of the flexor digitorum superficialis tendon secured to the d orsal surface of the repair site with a continuous stitch. Ultimate tensile strength, resistance to gap formation, and work of flexion were measured s imultaneously on an in situ tensile testing apparatus. No significant diffe rence in tensile strength was found between the augmented repair and the 6- strand Savage repair. The augmented repair and the 6-strand Savage repair s howed significantly greater ultimate tensile strength than the 2- and 4-str and repairs. The augmented repair had significantly greater resistance to 2 mm gap formation than the other 3 repairs. We were unable to show a signif icant difference in work of flexion between the repairs with the numbers te sted (n = 10). Our findings suggest that the augmented repair is strong eno ugh to tolerate the projected forces generated during active motion without dehiscence or gap formation at the repair site. Copyright (C) 2001 by the American Society for Surgery of the Hand.