The six-strand Tsuge cross technique prevents early gap formation in flexor tendon repair

With widespread implementation of rehabilitation by early active motion, preventing both early gap formation and failure are essential in flexor tendon repair. We studied the effect of various six-strand Tsuge techniques on early gap formation and strength in flexor tendon repair.

Thirty porcine flexor digitorum profundus tendons were divided into three groups: the conventional six-strand Tsuge technique (the Tsuge normal group) and two modified versions, the Tsuge cross and Tsuge cross short groups, in which two of three sutures were crossed with different purchase lengths. Fatigue strength (newtons × cycles) was determined using cyclic tensile testing on the repaired tendons with gradually increasing loads. The load (newtons) and number of tensile testing cycles when a 2 mm gap or failure occurred at the repair site were recorded.

Fatigue strength at 2 mm gap formation was significantly greater in the Tsuge cross and Tsuge cross short techniques than in the Tsuge normal technique. Fatigue strength at failure was significantly greater with the Tsuge cross short technique than with the Tsuge normal technique. Detailed analysis suggested that gap prevention using the Tsuge cross and Tsuge cross short techniques may be caused by tendon tightening by cross suturing.

The Tsuge cross and Tsuge cross short suture techniques prevent gap formation, which could hinder tendon healing during early active motion rehabilitation. The Tsuge cross short technique demonstrated a lower failure rate compared with the Tsuge normal technique; nevertheless, both the Tsuge cross and Tsuge cross short techniques had sufficient strength for early active motion.