Influence of the Tendon Grasping Technique on Tensile Strength in 6-strand Sutures

The locking configuration of the core suture in tendon repair considerably impacts the tendon's tensile strength. This study assessed the effects of two grasping techniques for 6-strand core sutures on gap formation resistance using linear load-to-failure testing under simulated tendon loading during active finger flexion.

Forty porcine flexor tendons were assigned to 3 groups and repaired using the Yoshizu #1 (Y1) technique or our novel 6-strand Yoshizu #3 (Y3) technique with or without peripheral sutures. The Y1 and Y3 techniques had similar suture configurations, but the Y1 technique involved 4 Kessler-type tendon anchorages and the Y3 technique 2 Lim and Tsai-type tendon grasping techniques. Repaired tendons were subjected to linear, noncyclic load-to-failure tensile testing. The initial gap, 2-mm gap force, and ultimate strength were measured.

Tendons repaired using the Y1 technique had a significantly lower mean load at the initial gap (9.4 N) than those repaired using the Y3 technique alone (26.8 N) and the Y3 technique with peripheral sutures (81.6 N). Average load at the 2-mm gap was greater following Y3 repair alone (38.1 N) and Y3 repair with peripheral sutures (94.3 N) than Y1 repair (22.4 N).

Significantly higher mean loads at the initial and 2-mm gap were obtained with the novel 6-strand Y3 technique compared to the 6-strand Y1 technique regardless of the use of peripheral sutures. These results suggested that Lim and Tsai-type tendon grasping is associated with greater gap resistance than Kessler-type tendon anchorage. In the Y3 technique, the use of peripheral sutures is particularly effective for enhancing the initial tension.

Surgeons should consider the impact of the tendon grasping technique on flexor tendon suturing. This novel 6-strand Y3 technique with peripheral sutures facilitates early active motion following primary flexor tendon repair.