Tensile Strength of Modified 4-Strand Cruciate Technique for Transversely or Obliquely Lacerated Tendons

Abstract

Purposes. To assess the tensile strength of the modified 4-strand cruciate technique for obliquely lacerated tendons, and to compare the findings with the strength of transversely lacerated tendons repaired at various grasping depths. Methods. 60 porcine front foot tendons were evenly divided into 4 groups. In groups 1 to 3, tendons were transversely lacerated and repaired with grasping points at both ends away from the laceration by 5 mm, 10 mm, and 15 mm respectively. In group 4, tendons were obliquely lacerated and repaired with a grasping point 5 mm away from the laceration on one end and 15 mm on the other. All tendons were repaired with a modified 4-strand core suture and continuous epitendinous suture, and then tested to failure in a tensile machine. Results. The tensile strength in group 1 was significantly lower than that in the other 3 groups (p<0.005). The tensile strength in group 4 was not significantly different from groups 2 and 3. Conclusion. The tensile strength of modified 4-strand cruciate repair configuration is not weakened in obliquely lacerated tendons; the grasping point at one end of the tendon being 15 mm away from laceration provides sufficient strength to compensate for the relatively weak 5-mm end. So long as one grasping point is away from the laceration site by 10 mm, the ultimate tensile strength of the transversely lacerated tendons appears acceptable. The modified 4-strand cruciate repair is safe to use for repairing obliquely lacerated tendons.