Mechanical analysis of tendon suture techniques.

The relative strengths of seven methods of tendon repair were measured by mechanical disruption in an effort to determine the quality of a technique using loaded criss-crossing sutures and a running epitenon stitch. Fifty-seven calcaneus tendons were harvested from adult New Zealand white rabbits and randomized for transection. Standardized oblique transections were repaired with nylon using modified Halsted peripheral suture; modified Kessler technique; Kessler core stitch alone; running peripheral epitenon stitch; modified Becker technique #1; modified Becker technique #2; and a new augmented Becker repair. Sixteen additional rabbits each had bilateral tendon repairs in situ, one leg by Kessler and the other by the new augmented Becker repair technique. Half were lethally injected after 2 weeks and half after 4 weeks. Tenorrhaphies were pulled apart at constant speed until a gap of 1 mm was observed. Strength (maximum stress) and toughness (energy absorption to gap formation) were calculated. At time 0 the new augmented Becker repairs were the strongest, followed by the Kessler and Becker #2 tenorrhaphies. Kessler repairs were weaker at 2 weeks and then gained in strength; new augmented Becker repairs did not weaken at the 2-week point and demonstrated significant gains in strength after 4 weeks in vivo. The new augmented Becker repair was the strongest by a significant margin at all time points.