Biomechanical comparisons of four-strand tendon repairs with double-stranded sutures: effects of different locks and suture geometry

Abstract

Multi-strand repairs are often used in flexor tendon surgery. We evaluated the strength of four four-strand tendon repairs with different locks and suture geometry. Forty-eight pig flexor tendons were repaired with the following methods: a cross-lock four-strand repair; a U-shaped repair with circle-locks; a modified Kessler repair with Pennington locks (with longitudinal sutures located more centrally; and another modified Kessler (with longitudinal sutures located more laterally). The tendons were loaded to complete failure of the repairs. The two Kessler repairs showed a 35% lower 2 mm gap force, and 15% lower ultimate strength compared with the other two repairs; the differences were of statistical significance. The failure pattern was breakage of sutures in almost all tendons. These four-strand repairs differed in gapping and ultimate strengths. The Kessler-type repairs with different geometry in the longitudinal sutures produced identical strengths. The Kessler-type repairs with Pennington locks were weaker than the two repairs with either cross-locks or circle-locks.

Biomechanical Analysis of the Modified Kessler, Lahey, Adelaide, and Becker Sutures for Flexor Tendon Repair

“…1,21e23 Some of the previous studies claimed a superior repair strength for the cross-lock configuration; 22,23 however, in our study, the gap formation appeared in all tested repairs at a similar tension force without a measurable difference between the locking-loop and the cross-lock configurations. This result is an extension to the finding of Xie and Tang 21 who demonstrated similar locking power for the cross-lock and circle-lock component.…”

“…It is possible that the applied pre-tension prevented potential differences in gap formation that would otherwise have been quantifiable, even if this effect is controversial. 22 Furthermore, we used a 3-0 core suture and a 5-0 epitendinous suture, which are both stronger than the 4-0 and 6-0 sutures used by many surgeons. 1,5,24,25 Throughout our testing, the 2-mm gap consistently occurred before failure of the epitendinous suture, which emphasizes the important role of this additional suture in order to avoid gap formation.…”

Regulatory effects of introduction of an exogenous FGF2 gene on other growth factor genes in a healing tendon

“…Tendon repair is one of the most difficult and unpredictable biological processes, which is often characterized clinically by postoperative gapping, disruption, and adhesion formation around tendon . So far, however, very few studies have been directed to molecular mechanism of tendon healing.…”

Effects of Tension Across the Tendon Repair Site on Tendon Gap and Ultimate Strength

“…The Kessler repair is a popular 2-strand method used clinically, and the 4-strand cross-lock method is reported to be an easy and reliable 4-strand repair. 7 Finally, we studied only cleanly cut tendons. Whether the needed pre-tension is similar for tendons with a clean cut or irregular lacerations is unknown.…”

“…These factors include the number of suture strands crossing the repair site, [1][2][3] suture materials, 4,5 incorporation of locking configuration to the repair, 3,6,7 length of suture purchase, 8,9 and modifications of peripheral sutures. 10 -12 However, past investigators have not specifically investigated how tension of the core suture affects repair strength.…”